Question: why did jamie kill her mom in halloween 4

title: Jamie Lloyd
text: Escaping from town , Jamie cowers in a pick - up truck as Rachel hits Michael head on , throwing him off the road and knocking him out . Despite Rachel 's orders , Jamie goes over to him and holds his hand . The police tell Jamie to drop to the ground and shoot Michael many times , causing him to fall into an abandoned mine shaft , which then collapses on top of him . Later , back in her foster home , Jamie is possessed by Michael 's spirit and stabs her foster mother , though not fatally . When screams are heard from upstairs , Dr. Loomis walks over to the staircase seeing Jamie poised at the top holding a pair of bloody scissors . Sheriff Ben Meeker ( Beau Starr ) restrains Loomis from shooting her . Jamie is now apparently consumed by Michael 's rage . 

Answer: answer: Jamie is possessed by Michael's spirit and stabs her foster mother, though not fatally.  Jamie is now apparently consumed by Michael's rage.