sibron new york argued decided june together peters new york argued december also appeal new york police officer patrol observed period man appellant sibron know information conversation six eight persons officer knew narcotics addicts later officer saw sibron restaurant three known addicts officer none occasions overheard conversation saw anything pass sibron others later officer ordered sibron outside restaurant officer said know sibron reached pocket officer reached pocket found envelopes containing heroin sibron charged unlawful possession heroin trial rejected sibron motion suppress heroin illegally seized holding officer probable cause make arrest seize heroin thereafter sibron pleaded guilty preserving right appeal evidentiary ruling sibron precluded obtaining bail pending appeal completed service sentence roughly two months physically possible present case appeal conviction affirmed intermediate state appellate new york appeals state initially sought justify search basis new york law code crim proc new york appeals apparently viewed authorizing search law provides police officer may stop person abroad public place reasonably suspects committing certain crimes may demand name address explanation actions officer suspects danger may search person dangerous weapon noted probable jurisdiction county district attorney confessed error officer home apartment lived years heard noise door peephole saw two strangers appellant peters another tiptoeing furtively hallway called police dressed armed service revolver observed two still engaged suspicious maneuvers believing attempting burglary officer pursued catching peters collar apartment hallway peters said visiting girl friend declined identify officer patted peters weapons discovered hard object thought might knife turned container burglar tools possession peters later charged trial denied peters motion suppress evidence refusing credit peters testimony visiting girl friend finding officer requisite reasonable suspicion stop question peters frisk dangerous weapon apartment hallway found public place within meaning statute peters pleaded guilty preserving right appeal rejection motion suppress intermediate appellate affirmed new york appeals held search justified parties sides contend principal issue cases constitutionality face held sibron completion service sentence moot appeal pp state may effectively deny convict access appellate courts release argue case mooted failure prevented even though sibron multiple offender substantial stake judgment conviction survives satisfaction sentence imposed fiswick followed pierre qualified pp confession error though entitled great weight relieve making examination record case conviction erroneously obtained particularly judgment state highest interpreting state statute challenged constitutional grounds confession error made local official rather official authorized speak state whole pp since question whether search seizure authorized whether reasonable fourth amendment pass upon facial constitutionality statute pp heroin illegally seized therefore inadmissible evidence pp search sibron justified incident lawful arrest since probable cause existed search pp adequate grounds officer search sibron weapons since officer reason believe sibron armed dangerous even arguably justification initial limited exploration arms officer thrust hand sibron pocket terry ohio ante distinguished pp search reasonable evidence seized admissible pp search peters incident lawful arrest fourth amendment pp arrest peters taken place search arrest officer authority search peters incident search limited scope justified need seize weapons well need prevent destruction evidence crime kalman finkel gretchen white oberman argued cause filed briefs appellant robert stuart friedman argued cause filed brief appellant william siegel argued cause appellee brief aaron koota james duggan argued cause appellee briefs leonard rubenfeld michael juviler argued cause district attorney new york county amicus curiae brief filed cases frank hogan richard uviller siegel argued cause district attorney kings county amicus curiae briefs amici curiae urging reversal cases filed jack greenberg james nabrit iii michael meltsner melvyn zarr anthony amsterdam naacp legal defense educational fund bernard berkman melvin wulf alan levine american civil liberties union et al louis lefkowitz pro se samuel hirshowitz first assistant attorney general maria marcus brenda soloff assistant attorneys general filed brief attorney general new york amicus curiae urging affirmance cases chief justice warren delivered opinion companion cases terry ohio ante decided today present related questions fourth fourteenth amendments cases arise context new york law code crim proc statute provides police officer may stop person abroad public place reasonably suspects committing committed commit felony offenses specified section five hundred chapter may demand name address explanation actions police officer stopped person questioning pursuant section reasonably suspects danger life limb may search person dangerous weapon police officer finds weapon thing possession may constitute crime may take keep completion questioning time shall either return lawfully possessed arrest person facts cases may stated briefly sibron appellant convicted unlawful possession heroin moved trial suppress heroin seized person arresting officer brooklyn patrolman anthony martin trial denied motion sibron pleaded guilty charge preserving right appeal evidentiary ruling hearing motion suppress officer martin testified patrolling beat uniform march observed sibron continually hours midnight vicinity broadway stated period time saw sibron conversation six eight persons patrolman martin knew past experience narcotics addicts officer testified overhear conversations see anything pass sibron others late evening sibron entered restaurant patrolman martin saw sibron speak three known addicts inside restaurant nothing overheard nothing seen pass sibron addicts sibron sat ordered pie coffee eating patrolman martin approached told come outside outside officer said sibron know according officer sibron mumbled something reached pocket simultaneously patrolman martin thrust hand pocket discovering several glassine envelopes turned contained heroin state difficulty settling upon theory admissibility envelopes heroin sworn complaint patrolman martin stated officer approached defendant latter direction officer seeing put hand left jacket pocket pulled tinfoil envelope attempt throw ground officer never losing sight said envelope seized def endan left hand examined found contain ten glascine sic envelopes white substance alleged heroin prosecutor theory hearing patrolman martin probable cause believe sibron possession narcotics seen conversing number known addicts period absence knowledge patrolman martin part concerning nature intercourse sibron addicts however trial inclined grant motion suppress judge stated knows unknown men narcotics addicts might talking world series might talking prize fights prosecutor however reminded judge sibron admitted stand patrolman martin absence talking addicts narcotics thereupon trial judge changed mind ruled officer probable cause arrest section statute mentioned point trial appellate term affirmed conviction without opinion appeals new york sibron case consolidated peters case appeals held search peters justified statute wrote opinion sibron case dissents judges fuld van voorhis however indicate rested holding rate brief opposition jurisdictional statement state sought justify search basis statute noted probable jurisdiction district attorney kings county confessed error peters appellant convicted possessing burglary tools circumstances evincing intent employ commission crime tools seized person time arrest like sibron made pretrial motion suppress trial denied motion pleaded guilty preserving right appeal officer samuel lasky new york city police department testified hearing motion home apartment mount vernon new york july finished taking shower drying heard noise door attempt investigate interrupted telephone call returned looked peephole hall officer lasky saw two men tiptoeing alcove toward stairway immediately called police put civilian clothes armed service revolver returning peephole saw tall man tiptoeing away alcove followed shorter man peters toward stairway officer lasky testified lived building years recognize either men tenants believing happened upon two men course attempted burglary officer lasky opened door entered hallway slammed door loudly behind precipitated flight stairs part two men officer lasky gave chase apartment located sixth floor apprehended peters fourth fifth floors grabbing peters collar continued another flight unsuccessful pursuit man peters explained presence building officer lasky saying visiting girl friend however declined reveal girl friend name ground married woman officer lasky patted peters weapons discovered hard object pocket stated hearing object feel like gun might knife removed object peters pocket opaque plastic envelope containing burglar tools trial explicitly refused credit peters testimony merely building visit girl friend found officer lasky requisite reasonable suspicion peters stop question also found peters response clearly unsatisfactory circumstances lasky action frisking peters dangerous weapon reasonable even though lasky armed held hallway apartment building public place within meaning statute appellate division affirmed without opinion appeals also affirmed essentially adopting reasoning trial judge judges fuld van voorhis dissenting separately first place clear broad dictum commenced discussion pierre case moot petitioner service sentence expiration longer subject matter judgment operate fails take account significant qualifications recognized pierre developed later cases days ago held unanimously writ habeas corpus available test constitutionality state conviction petitioner custody applied writ released adjudicate claims carafas lavallee numerous occasions past proceeded adjudicate merits criminal cases sentence fully served probationary period suspended sentence reimposed terminated ginsberg new york pollard morgan fiswick thus mere release prisoner mechanically foreclose consideration merits pierre recognized two possible exceptions doctrine mootness appear us applicable stated appear petitioner brought case review expiration sentence noting also petitioner conviction contempt controversy government continuing one good chance ample opportunity review important question presented merits future proceeding plain recognition vital importance keeping open avenues judicial review deprivations constitutional right way sibron bring case sentence expired statute precluded obtaining bail pending appeal virtue inevitable delays new york system released less month newly appointed appellate counsel supplied copy transcript roughly two months physically possible present case first tier state appellate system true despite fact took steps perfect appeal prompt diligent timely manner many deep abiding constitutional problems encountered primarily level low visibility criminal process context prosecutions minor offenses carry short sentences believe constitution contemplates people deprived constitutional rights level left utterly remediless defenseless repetitions unconstitutional conduct state may cut federal review whole classes cases simple expedient blanket denial bail pending appeal pierre clearly recognized state may effectively deny convict access appellate courts released argue case mooted failure alone prevented second exception recognized pierre permits adjudication merits criminal case either state federal law penalties disabilities imposed result judgment satisfied subsequent cases expanded exception point may realistically said inroads made upon principle pierre implied burden upon convict show existence collateral legal consequences three years later fiswick however held criminal case become moot upon release prisoner noting convict alien might subject deportation committed crime moral turpitude even though never held refused hold crime convicted fell category also pointed fact petitioner future decide wanted become american citizen might difficulty proving good moral character next case dealt problem collateral consequences morgan convict probably subjected higher sentence recidivist state account old federal conviction sought attack dissent pointed indication recidivist increment removed state sentence upon invalidation federal conviction chose rest holding case moot upon broader view matter without canvassing possible disabilities might imposed upon morgan alluding specifically recidivist sentence stated although term served results conviction may persist subsequent convictions may carry heavier penalties civil rights may affected power remedy invalid sentence exists think respondent entitled opportunity attempt show conviction invalid case certainly meets test survival without pausing canvass possibilities detail note new york expressly provides statute sibron conviction may used impeach character choose put issue future criminal trial code crim proc must submitted trial judge consideration sentencing sibron convicted crime code crim proc doubtless collateral consequences moreover see relevance fact sibron multiple offender morgan multiple offender see pollard see judge jury faced question character like sentencing judge may inclined forgive least discount limited number minor transgressions particularly occurred time relatively distant past impossible say point number convictions man record renders reputation irredeemable even believed individual reached point impossible us say interest beginning process redemption particular case sought adjudicated foretell opportunities might present future removal convictions individual record question validity criminal conviction arise many contexts compare burgett texas sooner issue fully litigated better concerned always preferable litigate matter directly principally dispute rather proceeding collateral central controversy moreover litigation better conducted dispute fresh additional facts may necessary taken without substantial risk witnesses die memories fade far better eliminate source potential legal disability require citizen suffer possibly unjustified consequences disability indefinite period time secure adjudication state right impose basis past action cf peyton rowe none concededly imperative policies behind constitutional rule entertaining moot controversies served dismissal case nothing abstract feigned hypothetical sibron appeal suggestion either sibron state wanting diligence fervor litigation us fully developed record testimony contested historical facts reflects impact actuality far greater degree many controversies accepted adjudication matter course federal declaratory judgment act pierre supra must read light later cases mean criminal case moot shown possibility collateral legal consequences imposed basis challenged conviction certainly case sibron substantial stake judgment conviction survives satisfaction sentence imposed fiswick supra case moot ii iii section unlike deals substantive validity certain types seizures searches without warrants purports authorize police officers stop people demand explanations search dangerous weapon certain circumstances upon reasonable suspicion engaged criminal activity represent danger policeman operative categories categories fourth amendment susceptible wide variety interpretations new york course free develop law search seizure meet needs local law enforcement see ker california process may call standards employs names may choose may however authorize police conduct trenches upon fourth amendment rights regardless labels attaches conduct question upon review search seizure whether search seizure authorized state law question rather whether search reasonable fourth amendment search authorized state law may unreasonable one amendment may search expressly authorized state law justified constitutionally reasonable one cooper california accordingly make pronouncement facial constitutionality constitutional point respect statute peculiar sort appeals new york recognized much language employed conduct authorizes people peters held today terry ohio ante police conduct sort deals must judged reasonable search seizure clause fourth amendment inquiry clause may differ sharply inquiry set categories constitutional inquiry furthered attempt pronounce judgment words statute must confine review instead reasonableness searches seizures underlie two convictions iv patrolman martin lacked probable cause arrest however seizure search sibron might still justified outset reasonable grounds believe sibron armed dangerous terry ohio ante called upon decide case whether seizure sibron inside restaurant antecedent physical seizure accompanied search record unclear respect transpired sibron officer inside restaurant totally barren indication whether sibron accompanied patrolman martin outside submission show force authority left choice whether went voluntarily spirit apparent cooperation officer investigation event deficiency record immaterial since patrolman martin obtained new information interval initiation encounter restaurant physical seizure search sibron outside although appeals new york wrote opinion case seems viewed search search weapons affirmed basis authorizes search officer reasonably suspects danger life limb appeals rate justified searches field interrogation ground answer question propounded policeman may bullet case exposure danger great people rivera cert denied application reasoning facts case proves much police officer entitled seize search every person sees street makes inquiries places hand person citizen search anything must constitutionally adequate reasonable grounds case search weapons must able point particular facts reasonably inferred individual armed dangerous terry ohio supra patrolman martin testimony reveals facts suspect mere act talking number known narcotics addicts period gives rise reasonable fear life limb part police officer justifies arrest committing crime patrolman martin urge sibron put hand pocket feared going weapon acted opening statement sibron know made abundantly clear sought narcotics testimony hearing left doubt thought narcotics sibron pocket even assuming arguendo adequate grounds search sibron weapons nature scope search conducted patrolman martin clearly unrelated justification render heroin inadmissible search weapons approved terry consisted solely limited patting outer clothing suspect concealed objects might used instruments assault discovered objects officer terry place hands pockets men searched case attempt initial limited exploration arms patrolman martin thrust hand sibron pocket took envelopes heroin testimony shows looking narcotics found search reasonably limited scope accomplishment goal might conceivably justified inception protection officer disarming potentially dangerous man search violates guarantee fourth amendment protects sanctity person unreasonable intrusions part government agents noted sibron case search incident lawful arrest may precede arrest serve part justification question fact precisely case arrest took place rios inconclusive discussion trial concerning officer lasky arrested peters clear arrest purposes constitutional justification already taken place search commenced policeman grabbed peters collar abruptly seized curtailed freedom movement basis probable cause believe engaged criminal activity see henry supra point authority search peters incident search obviously justified need seize weapons things might used assault officer effect escape well need prevent destruction evidence crime preston moreover reasonably limited scope purposes officer lasky engage unrestrained examination peters personal effects seized cut short flight searched primarily weapons patting outer clothing officer lasky discovered object pocket might used weapon seized discovered potential instrument crime burglary concluded peters conviction fully comports commands fourth fourteenth amendments must affirmed conviction however must reversed ground heroin unconstitutionally admitted evidence appellant ordered footnotes code crim proc provides order denying motion suppress evidence criminal case may reviewed appeal judgment conviction notwithstanding fact judgment conviction predicated upon plea guilty patrolman martin stated several times put hand sibron pocket seized heroin sibron opportunity remove hand pocket trial questioned point say time reached pocket handed packets drop packets drop know intentions pushed hand pocket joseph prosecutor intercepted officer witness yes emphasis added possibility sibron never far appears record offered resistance might posed danger patrolman martin safety never even discussed potential justification search mention weapons officer entire testimony came response leading question sibron counsel martin stated thought sibron might reaching gun even patrolman martin accept suggestion opposition regarding reason action discussion continued upon plain premise looking narcotics time pen law made possession tools circumstances misdemeanor first offenders felony previously convicted crime peters convicted felony section officer lasky testified called police immediately leaving apartment told sergeant desk two burglars floor officer lasky testified emerged apartment slammed door gun ran stairs sworn affidavit assistant district attorney trial ruled motion suppress stated apprehended peters fleeing steps building trial explicitly took note flight peters companion factor contributing officer lasky reasonable suspicion think testimony hearing require laboring aspect matter unless one believe legitimately normal man public hall apartment house visit unidentified observed another tenant rapidly descend stairway presence elevators first suggestion mootness case came upon oral argument revealed first time appellant released fact appear record despite fact release occurred well two years case argued mootness hinted state brief opposition jurisdictional statement took position decision clearly right merit review brief merits conceded decision clearly violated sibron constitutional rights urged aberrant interpretation impair constitutionality new york statute following suggestion mootness oral argument moreover state filed brief amplified views case held moot added extraordinary suggestion ignore problem pronounce upon constitutionality statute case become moot normally circumstances consider fully justified foreclosing party upon issue however since question goes existence controversy us adjudicate undertaken review cf fay noia onventional notions finality criminal litigation permitted defeat manifest federal policy federal constitutional rights personal liberty shall denied without fullest opportunity plenary federal judicial review see code crim proc subd sibron arrested march unable make bail trial indigency thus remained jail time expiration sentence good time credit july convicted april application leave proceed forma pauperis granted may assigned appellate counsel provided transcript june appellate term recessed june september thus sibron released well opportunity even argue case intermediate state appellate decision appeals new york july anniversary sibron release thompson city louisville pierre noted petitioner taken steps preserve case apply stay supersedeas however abundantly clear procedure sibron availed prevent expiration sentence long hear case supersedeas purely ancillary writ may issue connection appeal actually taken ex parte ralston sup rule see robertson kirkham jurisdiction wolfson kurland time sibron completed service sentence judgment outstanding conviction rendered criminal city new york county kings jurisdiction hear appeal judgment since rendered highest state decision warrant interference orderly appellate processes state courts thus supersedeas issued ordered sibron admitted bail expiration sentence since offense bailable see supra thus case distinguishable pierre sibron brought case review expiration sentence compare ginsberg new york held mere possibility commissioner buildings town hempstead new york might discretion attempt future revoke license run luncheonette single conviction selling relatively inoffensive girlie magazines boy sufficient preserve criminal case mootness see generally note rev know record many convictions sibron crimes rendered hearing admitted conviction burglary misdemeanor conviction possession narcotics also admitted convictions none specifically alluded note clear distinction general impairment credibility referred pierre see new york specific statutory authorization use conviction impeach character defendant criminal proceeding latter clear legal disability deliberately specifically imposed legislature factor clearly considered relevant past determining issue mootness see fiswick frankfurter note advisory opinions harv rev see also parker ellis dissenting opinion apparent example whether power stop granted statute entails power detain investigation interrogation upon less probable cause sort durational limitations upon detention contemplated statute apparent grant power compulsion indicates many stops constitute seizures clear conduct analyzed rubric statute either rise level seizure based upon less probable cause peters case example new york courts justified seizure appellant concluded fact probable cause arrest officer lasky seized peters stairway see infra event pronouncement upon abstract validity stop category inappropriate cases since concluded neither presents question validity seizure person purposes interrogation upon less probable cause statute categories equally elastic passed recently state highest ruled upon many questions involving potential intersections federal constitutional guarantees tell example whether officer power demand person explanation actions contemplates either obligation part citizen answer additional power part officer event refusal answer even whether interrogation following stop custodial compare miranda arizona moreover substantial indications statutory category search dangerous weapon may encompass conduct considerably broader scope approved terry ohio ante see infra see also people taggart least activity apparently permitted rubric searching dangerous weapons may thus permissible constitution reasonable suspicion criminal activity rises level probable cause finally impossible tell whether standard reasonable suspicion connotes sort specificity reliability objectivity touchstone permissible governmental action fourth amendment compare terry ohio supra people taggart supra connection note searches seizures sibron peters upheld appeals new york predicated upon reasonable suspicion whereas concluded officer peters probable cause arrest policeman sibron possessed information justify intrusion upon rights protected fourth amendment argued dissent effect overturned factual findings two courts search case measure part patrolman martin thought sibron might reaching gun true noted appeals new york apparently rested approval search view trial however made finding fact trial judge adopted theory prosecution hearing motion suppress theory probable cause arrest sibron crime narcotics fact tipped scales trial nothing danger policeman judge expressly changed original view held heroin admissible upon reminded sibron admitted stand spoke addicts narcotics admission relevant issue probable cause understand dissent take position prior discovery heroin probable cause arrest moreover patrolman martin never time put forth notion acted protect noted subject never came examination defense counsel raised question whether patrolman martin thought sibron going gun see supra reference weapons point hearing subject swiftly dropped circumstances unarticulated finding appellate wrote opinion apparently effect officer invasion sibron person comported constitution need protect deserving controlling deference see supra justice douglas concurring officer martin testified night question observed appellant sibron continually midnight period sibron conversed different persons personally known martin narcotics addicts sibron entered restaurant martin followed inside observed sibron talking three persons also personally known martin narcotics addicts point approached sibron asked come outside sibron stepped martin said know sibron reached inside pocket time martin reached pocket discovered several glassine envelopes found contain heroin sibron subsequently convicted unlawful possession heroin consorting criminals may particular factual setting basis believing criminal project underway yet talking addicts without rises higher suspicion sufficient seizure search thing privacy vast group sick people justice douglas concurring officer lasky testified resided apartment house mount vernon new york apartment sixth floor afternoon stepped shower drying heard noise door phone rang answered call hanging looked peephole door saw two men one appellant alcove toward stairway phoned headquarters report occurrence put clothes proceeded back door time saw tall man tiptoeing away alcove followed appellant toward stairway lasky came apartment slammed door behind gave chase gun hand two men began run stairs apprehended appellant stairway fourth fifth floors asked building appellant replied looking girl friend refused give name saying married woman lasky frisked appellant weapon discovered right pants pocket plastic envelope envelope contained tension bar picks allen wrenches short leg filed screwdriver edge appellant subsequently convicted possession burglary tools hold time lasky seized appellant probable cause believe appellant kind burglary housebreaking mission view probable cause seize appellant accordingly conduct limited search person weapons see pen code justice white concurring join parts opinion respect appellant peters join affirmance conviction probable cause arrest question reach probable cause stop peters questioning thus frisk dangerous weapons see concurring opinion terry ohio ante patting peters clothing officer discovered object pocket might used weapon ante object turned package burglar tools view tools properly admitted evidence justice fortas concurring construe pierre light later cases mean criminal case moot appears collateral legal consequences imposed basis challenged conviction cf majority opinion ante join without qualification judgment opinion concerning standards used determining whether applied particular situations constitutional explicitly reserve possibility statute purporting authorize warrantless search might extreme justify concluding unconstitutional face regardless facts particular case extent opinion may indicate contrary disagree cf majority opinion ante sibron case conclude find nothing record case pertinent principles law cause us disregard confession error counsel kings county discourage confessions error disregard cf majority opinion pt ii ante justice harlan concurring result fully agree results reached cases think consonant dictated decision terry ohio ante reasons understand however declined rest judgments upon principles terry least one particular made serious inroads upon protection afforded fourth fourteenth amendments course entirely correct concluding pass upon constitutionality new york law face statute certainly unconstitutional face plainly purport authorize unconstitutional activities policemen constitutional face expression means action later thought fall within terms statute ipso facto within constitutional limits well statute state federal receives imprimatur mean however statute ignored state new york made deliberate effort deal complex problem policework without giving carte blanche particular verbal formulation think relevant indicate extent effort constitutionally successful core new york statute permission stop person reasonably suspected crime decision terry right stop may indeed premised reasonable suspicion require probable cause hence new york formulation extent constitutional mean suspicion need reasonable constitutional well statutory sense mean approved momentary stop indicated questioning may constitutionally occur stop cases us raise questions turning individual cases agree conviction sibron reversed upon premises terry outset agree sufficient collateral legal consequences sibron conviction shown prevent case moot agree case reversed simply state confession error considerable confusion surrounded search frisk sibron led actual recovery heroin seems irrelevant purposes officer martin repudiated first statement might conceivably indicated theory abandonment see ante matter theories adopted clear least forcible frisk comparable occurred terry requires constitutional justification since carrying heroin crime new york probable cause believe sibron carrying heroin also probable cause arrest says officer martin clearly neither although sibron conversations several known addicts done nothing several hours surveillance made probable either carrying heroin engaging transactions acquaintances reasonable grounds stop short arrest accept adequate general formula new york requirement officer must reasonably suspect person stops committing committed commit felony code crim proc face requirement anything stringent requirement stated terry police officer observes unusual conduct leads reasonably conclude light experience criminal activity may afoot ante interpretation new york statute course matter new york courts particular stop must meet terry standard well forcible encounter officer martin sibron meet terry reasonableness standard first place although association known criminals may think properly factor contributing suspiciousness circumstances entirely create suspicion adequate support stop must something least activities person observed surroundings affirmatively suggests particular criminal activity completed current intended case terry palpably case eight continuous hours point interrupted sibron eating piece pie officer martin apparently observed single suspicious action heard single suspicious word part sibron person associated anything period surveillance pointed away suspicion furthermore terry police officer judged suspect commit violent crime assert order prevent reason officer martin think incipient crime flight destruction evidence occur stayed hand indeed reason intrude upon sibron moment four hours earlier reason think situation changed four hours later rule drawn suggest one important factor missing taken account determining whether reasonable grounds forcible intrusion whether need immediate action reasons hold officer martin lacked reasonable grounds intrude forcibly upon sibron consequence essential premise right conduct frisk lacking see concurring opinion terry ante therefore find unnecessary reach two troublesome questions first although think terry right frisk automatic officer lawfully stops person suspected crime whose nature creates substantial likelihood armed clear suspected possession narcotics falls category nature suspected offense creates reasonable apprehension officer safety permit frisk unless circumstances second agree even frisk proper scope limited adequate purposes see need resolve question whether frisk exceeded bounds turning peters agree conviction upheld differ strongly fundamentally approach holds burglar tools recovered peters search incident lawful arrest think officer lasky anything close probable cause arrest peters recovered burglar tools indeed probable cause existed find difficult see different rationale necessary support stop frisk terry new york devote much thought constitutional problems field interrogation case latest exceedingly small number cases indicating suffices probable cause noted terry influence police tactics field necessarily limited influence decision hundreds courts magistrates decide whether probable cause real arrest full search large officer lasky testified afternoon heard noise door apartment testify state conclude led believe someone sought force entry ante looked public hallway saw two men recognize surely strange occurrence large apartment building one appeared lasky testify man either behaving furtively ibid lasky left apartment ran gun hand testify flight ante though flight approach stranger lasky apparently uniform hardly indicative mens rea probable cause arrest means evidence warrant prudent reasonable man magistrate actual hypothetical believing particular person committed committing crime officer lasky extrinsic reason think crime committed whether proper issue warrant depends entirely statements observations men apart conclusory statement thought men burglars offered little specific evidence find hard believe peters made good escape report burglary neighborhood hold proper prudent neutral magistrate issue warrant arrest course upholding peters conviction makes two points may lead future confusion first concerns moment arrest escalating encounter policeman citizen beginning perhaps friendly conversation ending imprisonment evidence developing encounter may important identify moment arrest moment policeman permitted proceed unless probable cause problem premises way involved case holds officer lasky probable cause arrest moment caught peters hence probable cause clearly preceded anything might thought arrest implies however although problem whether arrest peters occurred late enough probable cause developed might problem whether occurred early enough peters searched seems false problem course fruits search may used justify arrest incident means probable cause arrest must precede search prosecution shows probable cause arrest prior search man person met total burden case defendant may validly say although officer right arrest moment seized searched person search invalid fact arrest afterwards fact important demonstrated terry every curtailment freedom movement arrest requiring antecedent probable cause time officer probable cause may course seize search immediately hence certain police actions undoubtedly turn encounter arrest requiring antecedent probable cause prosecution must able date arrest early chooses following development probable cause second possible source confusion statement officer lasky engage unrestrained examination peters personal effects ante since found probable cause arrest peters since officer arresting probable cause entitled make full incident search assume merely factual observation factual matter agree although articulable circumstances somewhat less suspicious terry affirm terry ground officer lasky reasonable cause make forced stop unlike probable cause arrest reasonable grounds stop depend degree likelihood crime committed officer may forcibly intrude upon incipient crime even make arrest simple reason nothing arrest anyone hence although officer lasky small reason believe crime committed right stop peters justified reasonable suspicion peters attempt burglary clear officer act quickly going act stated seems immediate action obviously required police officer justified acting rather less objectively articulable evidence time consideration alternative courses action perhaps important opinion terry emphasized special qualifications experienced police officer probable cause arrest search always depended existence hard evidence persuade reasonable man judging encounters seems proper take account police officer trained instinctive judgment operating multitude small gestures actions impossible reconstruct thus statement officer looked like burglar adds little affidavit filed magistrate effort obtain warrant question whether reasonable take limited forcible steps situation requiring immediate action however statement looms larger course entitled disbelieve officer subject believes articulable supporting facts entitled find action taken fire reasonable given officer lasky statement circumstances crediting experienced judgment watched two men state courts entitled conclude lasky forcibly stopped peters reasonable suspicion frisk made incident stop limited one turned burglar tools although frisk constitutionally permitted order protect officer lawful state course entitled use contraband appears foregoing reasons concur result cases thoughtful study many points see ali model code procedure tentative draft commentary sections appearing true new york courts attributed statement attribution seems unwarranted record beck ohio rios henry henry supra said constitutional standard felony arrests fbi agents without warrant section authorized agents make arrests without warrant offense committed presence felony cognizable laws reasonable grounds believe person arrested committed committing felony ker california parallel standard applicable warrantless arrests state local police compare henry said far enough evidence justify magistrate issuing warrant agents knew federal crime theft whisky interstate shipment committed neighborhood petitioner observed driving alley picking packages driving away agree facts constitute probable cause find hard see evidence impressive leading case rabinowitz justice black concurring dissenting concur affirmance judgment peters dissent reversal sibron new york affirm conviction sibron convicted violating new york law basis evidence seized police reverses ground narcotics seized result unreasonable search violation fourth amendment decided today terry ohio peters new york policeman violate fourth amendment makes limited search weapons person man policeman probable cause believe dangerous weapon might injure policeman others unless searched weapon taken away course established principles violation fourth amendment policeman search person probable cause believe committing felony time reasons think seizure narcotics sibron unreasonable fourth amendment different emphasis facts find necessary restate patrolman martin saw appellant sibron vicinity broadway midnight sibron remained time policeman saw sibron talking six eight persons policeman knew past experience narcotics addicts later sibron went restaurant patrolman saw sibron speak three known addicts sibron eating restaurant policeman went asked come sibron came officer said sibron know sibron mumbled something reached left coat pocket officer also moved hand pocket seized turned heroin patrolman testified hearing suppress use heroin evidence thought sibron might reaching gun counsel new york reason able understand attempted confess error reason search seizure violated fourth amendment agree need accept confession error unlike think two reasons seizure violate fourth amendment heroin properly admitted evidence first think probable cause policeman believe sibron reached hand coat pocket sibron dangerous weapon might use taken away according opinion seems ground appeals new york justified search since affirmed basis authorizes search officer reasonably suspects danger life limb ante seems reasonable inference sibron approaching talking addicts eight hours reached hand quickly left coat pocket might well reaching gun emphasized today opinions cases policeman circumstances act split second delay may mean death one know addict may moved shoot stab particularly moves hand hurriedly pocket weapons known habitually carried behooves officer wants live act officer true officer might also thought sibron get heroin instead weapon law enforcement officers nation gained little protection courts opinions left helpless act self defense man associating intimately continuously addicts upon meeting officer shifts hand immediately pocket weapons constantly carried appraising facts realize chosen draw inferences different mine drawn courts illustration draws inferences officer testimony hearing continued upon plain premise looking narcotics time ante hardly distance place atmosphere trial position overturn trial appellate courts independent finding unspoken premise officer inner thoughts acting upon findings rejecting lower state courts sitting marble halls building washington cautious due holding mapp ohio due get review literally thousands cases raising questions like us setting meticulously review findings task endless many rue day mapp decided wise imperative findings facts reasonableness probable cause involved state cases overturn state findings unless extravagant egregious errors seems fantastic even suggest case leave state holdings alone second think also sufficient evidence base findings recovery heroin particular officer reasonably believe probable cause charge sibron violating new york narcotics laws previously argued think ample evidence give officer probable cause believe sibron dangerous weapon might use circumstances officer right search limited fashion since therefore reasonable justified search use heroin discovered admissible evidence affirm