(SOLVED) sci-fi movie from the 1980s or early 1990s where a teenage boy uses some sort of laser gun

There’s a teenage boy who lives in a trailer. A group of bullies picking on him turn him upside down and he bites the ankle of one of them. A man living in the trailer with the boy who I assumed to be either his dad or stepdad goes into his room and starts smashing everything with a baseball bat. The boy then somehow gets this laser gun and uses it to kill the man. The boy then goes and uses it in front of the bullies in order to intimidate them.