Drive-In Massacre (1976)

There's murders taking place at a Southern California drive in, and the cops are investigating, but who is responsible? Is it Germy, the former carnival geek who now does the cleaning up around there? He is pretty spun, and his former friends were chickens from the carnival he worked at, so he's a likely candidate. So is the drive-in's manager, who is a bitter man who is overworked and underpaid and dresses like he's the devil or something. Or is it the local voyeur, who is on parole (or probation) and doesn't want his neighbors to know he's a pervert? At any rate, we have some rather unrealistic decapitations and even a sword through a neck that also looks rather unrealistic, and it's always young couples just on the verge of getting it on. The cops even go undercover, one dressed in drag, to find our killer but to no avail. Is the mystery ever solved?