Stephen Cooney

There is this movie that I can't remember the name of - I saw in on TV back in the mid 90's. It was about a little boy who kept killing his family members. I don't remember much of it but there was a scene where the boy's grandmother was in the hospital on one of those breathing machines and the boy went and unplugged it so she died. I think he also pushed someone else into a pool who drowned. I know it's a long shot but if anyone can help me name this movie, I'd be so appreciative. Thank you.