stirone argued decided january petitioner indicted convicted federal district interfering interstate commerce extortion violation hobbs act interstate commerce mentioned indictment importation pennsylvania sand used building steel plant trial judge permitted introduction evidence show interference also exportation pennsylvania steel manufactured new plant instructed jury base conviction upon interference either importation sand exportation steel held conviction reversed pp since indictment charge interference exportation steel state prejudicial error submit jury question whether extortion interfered exportation steel pp variance pleading proof involved insignificant may dismissed harmless error deprived petitioner substantial right tried felony charges presented indictment returned grand jury pp since jury might based conviction finding interference exportation steel conviction must reversed michael von moschzisker argued cause petitioner brief vincent casey wayne barnett argued cause brief solicitor general rankin assistant attorney general wilkey ralph spritzer beatrice rosenberg theodore george gilinsky justice black delivered opinion petitioner nicholas stirone indicted convicted federal unlawfully interfering interstate commerce violation hobbs act crucial question whether convicted offense charged indictment far relevant question indictment charged following man name william rider contract supply concrete plant pennsylvania used erection plant allenport pennsylvania purpose performing contract rider caused supplies materials sand move interstate commerce various points site plant manufacture mixing ready mixed concrete particularly outside state pennsylvania state pennsylvania unlawfully obstruct delay affect interstate commerce several movement aforesaid materials supplies commerce extortion induced fear wrongful use threats labor disputes threats loss obstruction prevention performance contract supply ready mixed concrete agree appeals rider dependence shipments sand outside pennsylvania carry concrete business entitled hobbs act protection interruption stoppage commerce sand extortion kind jury found petitioner committed act speaks broad language manifesting purpose use constitutional power congress punish interference interstate commerce extortion robbery physical violence act outlaws interference way degree rider business hindered destroyed interstate movements sand slackened stopped trial jury entitled find commerce saved blockage rider compliance stirone coercive illegal demands free commerce destructive burdens hobbs act passed green whether prospective steel shipments new steel mills enough alone bring transaction act difficult question need decide however since agree dissenting judges appeals error submit question jury error dismissed merely insignificant variance allegation proof thus harmless error berger crime charged felony fifth amendment requires prosecution begun indictment ever since ex parte bain decided rule indictment returned charges may broadened amendment except grand jury case ordered specific relevant allegations grand jury charged stricken indictment bain might convicted without proof particular allegations holding done justice miller speaking said lies within province change charging part indictment suit notions grand jury probably made attention called suggested changes great importance common law attaches indictment grand jury prerequisite prisoner trial crime without constitution says person shall held answer may frittered away value almost destroyed indictment changed longer indictment grand jury presented doctrine place rights citizen intended protected constitutional provision mercy control prosecuting attorney trial charged jury two essential elements hobbs act crime interference commerce extortion elements charged neither surplusage neither treated surplusage charge interstate commerce affected critical since federal government jurisdiction crime rests interference follows one particular kind commerce charged burdened conviction must rest charge another even though assumed indictment drawn general terms conviction might rest upon showing commerce one kind another burdened right grand jury make charge judgment substantial right taken away without amendment bain case know whether grand jury included indictment charge commerce steel nonexistent steel mill interfered yet admission evidence charge might basis upon trial jury convicted petitioner convicted charge grand jury never made fatal error cf cole arkansas de jonge oregon reversed footnotes bain indicted making false statement intent deceive comptroller currency agent appointed examine affairs said association sustaining demurrers bain indictment trial went say thereupon motion counsel orders indictment amended striking words comptroller currency therein contained amendment intended permit conviction bain without proof deceived comptroller grand jury charged yet institution grand jury adopted country continued considerations similar give chief value england designed means bringing trial persons accused public offences upon grounds also means protecting citizen unfounded accusation whether comes government prompted partisan passion private enmity person shall required according fundamental law country except cases mentioned answer higher crimes unless body consisting less sixteen good lawful men selected body district shall declare upon careful deliberation solemnity oath good reason accusation trial ex parte bain see also costello