▁May ▁that ▁an ▁" I sl am istic ▁background " ▁was ▁likely . ▁ ▁Later ▁that ▁day , ▁it ▁was ▁reported ▁that ▁the ▁perpet r ator ▁had ▁drug ▁and ▁mental ▁problems ▁and ▁was ▁treated ▁two ▁days ▁earlier . ▁The ▁assumption ▁that ▁the ▁attack er ▁was ▁an ▁Islam ist ▁was ▁ruled ▁out , ▁but ▁a ▁political ▁mot ive ▁is ▁still ▁being ▁considered , ▁though ▁the ▁attack er ▁appeared ▁to ▁be ▁confused ▁during ▁the ▁inter rog ation . ▁The ▁perpet r ator ▁was ▁not ▁co oper ating ▁during ▁first ▁inter rog ation , ▁but ▁he ▁later ▁admitted ▁to ▁comm itting ▁the ▁attack . ▁No ▁links ▁to ▁terror ist ▁networks ▁were ▁known . ▁The ▁police ▁established ▁a ▁special ▁commission , ▁consisting ▁of ▁ 8 0 ▁officers . ▁The ▁perpet r ator ' s ▁cell ▁phone ▁and ▁table t ▁computer ▁were ▁found ▁and ▁evaluated ; ▁in ▁addition , ▁C CT V ▁record ings ▁from ▁the ▁train ▁and ▁station ▁were ▁investig ated . ▁ ▁Security ▁measures ▁Service ▁at ▁the ▁train ▁station ▁was ▁tempor arily ▁closed ▁to ▁allow ▁authorities ▁to ▁conduct ▁their ▁investigation . ▁ ▁The ▁attack ▁caused ▁the ▁New ▁York ▁City ▁Police ▁Department ▁to ▁tempor arily ▁increase ▁security ▁on ▁the ▁New ▁York ▁City ▁Sub way ▁system ▁while ▁investig ators ▁looked ▁into ▁possible ▁connections ▁to ▁international ▁milit ant ▁organizations . ▁ ▁Disc uss ions ▁made ▁in ▁the ▁w ake ▁of ▁the ▁attack ▁raised ▁the ▁possibility ▁that ▁bag ▁checks ▁at ▁German ▁train ▁stations ▁might ▁have ▁found ▁the ▁kn ife ▁used ▁in ▁the ▁attack ▁and ▁prevent ed ▁it ▁from ▁happening ,