Whats The Name Of This Movie?

i was a kid the last time i seen it i remember there was this teenager and he had a dog named like bon jovi or something but he finds this top secret gun that the goverment had lost and he thinks it came from aliens and he kills his dad cuz his dad killed his dog and the goverment gets after him and in the end he's in a field asking where the mothership is and they kill him it has to be a late 80's movie so if my description rings a bell let me know thanks