The killer is the handyman Howie (Brad Rowe). Christina's (Allison Lange's) mother sent him there to kill the family and he really isn't a handyman. However, Christina, her brother and father make it out alive and continue to reside in the house. At the very end, the mother (Chilton Crane) has convinced another man to leave the mental hospital to kill the family.
Thanks, Serena J!
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