▁At ▁the ▁same ▁time ▁that ▁K arr as ▁died , ▁a ▁criminal ▁by ▁the ▁name ▁of ▁James ▁Ven am un ▁( the ▁inf am ous ▁" G em ini ▁K iller ") ▁was ▁executed . ▁The ▁demon ▁left ▁the ▁body ▁of ▁the ▁dead ▁K arr as ▁and ▁placed ▁Ven am un ' s ▁soul ▁into ▁K arr as ' s ▁body ▁as ▁a ▁means ▁of ▁reven ge ▁for ▁having ▁been ▁thrown ▁out ▁of ▁Reg an ▁Mac Ne il ' s . ▁The ▁body ▁was ▁switched ▁prior ▁to ▁inter ment ▁and ▁an ▁am nes iac ▁K arr as ▁was ▁found ▁ro aming ▁the ▁streets ▁of ▁Washington ▁DC . ▁So on , ▁he ▁was ▁placed ▁under ▁the ▁care ▁of ▁a ▁mental ▁hospital . ▁He ▁remained ▁in ▁cell ▁# 1 1 ▁for ▁ 1 5 ▁years . ▁ ▁His ▁brain ▁and ▁b one ▁t issues ▁m ended ▁over ▁time , ▁but ▁he ▁altern ated ▁between ▁his ▁own ▁person ality ▁and ▁that ▁of ▁Ven am un . ▁Also , ▁the ▁spirit ▁of ▁Ven am un ▁left ▁K arr as ' s ▁body ▁by ▁night ▁to ▁in va de ▁the ▁other ▁patients ▁in ▁the ▁w ard , ▁making ▁them ▁commit ▁mur ders ▁for ▁him ▁without ▁Ven am un ▁taking ▁the ▁bl ame . ▁The ▁Gem ini ▁K iller ▁had ▁come ▁back ▁to ▁w re ak ▁hav oc . ▁ ▁In ▁the ▁film , ▁during ▁the ▁course ▁of ▁an ▁ex or c ism , ▁Ven am un ▁is ▁forced ▁to ▁abandon ▁K arr as ' s ▁body ▁and ▁L