Two satanist brothers and two cops [SOLVED]

[Neville]

OK, I saw this one on TV ages ago, so I guess it must be a 1970s-80s film. It's a dark comedy with lots of gore. The plot involves two brothers who need to complete a satanic ritual his father couldn't finish because he slept with the virgin woman, and apparently she was a crucial element.

There were also a couple of police officers, a man and a woman, who start investigating the tons of corpses the brothers leave behind.

Any ideas?

[Dubal]

Gonna guess Blood Diner.

[Neville]

I don'¡t remember the plot involving a diner, but that one actually has all the numbers to be the film I was looking for. Thank you very much.

EDIT: IT IS THE ONE. Oh, man, thanks again.