washington/new york u.s. congressional committee demand former drug executive martin shkreli appear hear drug price testify former company decision raise price lifesaving medicine 5,000 percent congressional aid say wednesday shkreli separately face federal criminal charge defraud investors serve subpoena appear jan. 26 u.s. house representatives committee oversight government reform aid say senate special committee age also investigate company drug price practice say wednesday shkreli invoke u.s. constitution fifth amendment self-incrimination refuse produce subpoena document shkreli 32 fire back lawmakers twitter write wednesday house busy whine healthcare reporters appear chit chat next week decide yet decline interview request outspoken entrepreneur spark firestorm last year raise price daraprim decades-old treatment dangerous parasitic infection 750 pill 13.50 acquire medicine sell pill shkreli plead guilty last month criminal charge run company like ponzi scheme use subsequent company pay defraud investors prior company arrest step chief executive turing pharmaceuticals fire chief executive kalobios pharmaceuticals inc. kalobios also file chapter 11 bankruptcy shkreli past company also include retrophin inc sue allege mismanagement testify congress risky someone face criminal charge chance could say something prosecutors would late use trial reason many witness invoke fifth amendment refuse answer question even travel washington shkreli require first get sign-off federal judge release bond restrict certain part new york state however judge typically grant temporary travel waivers white-collar defendants u.s. representative elijah cummings maryland top democrat oversight committee say hear give shkreli chance explain view drug price try good part year get information martin shkreli outrageous price increase obstruct investigation every turn cummings say statement u.s. congressional committee subpoena ex-drug ceo shkreli