Teen watches hypnotic videotape; kills his friends

[SomeoneElse]

I saw this movie(?) in the late 90's.

I don't remember the setup well, but a teen watches a series of 5(?) mysterious videotapes, as part of some sort of game or real-life murder mystery. People around him start to go missing/die. I think it might start with a pet, and quickly escalate. He finds a finger in his freezer. The twist is that the videos have been hypnotizing him, and he has been the culprit all along.

[monstermoviemadness]

Don't know, sorry, but you might also want to check out the IMDB. The users are very helpful, sadly not all questions are answered, though, but hey, what can you do, right?

[staircars]

I think this is Brainscan (1994). Edward Furlong's character plays an immersive video game in which he has to kill people, then people in the neighbourhood start going missing... He finds a foot in his fridge and there's a dog in the film but I don't recall any pets being killed.

The film veers between atmospheric horror and ridiculous villainy, courtesy of 'The Trickster', so it's quite uneven. Frank Langella plays the detective investigating the murders.

[jockland]

Benny's Tape (1992).  About a dissociated teenage boy obscessed with a video showing the slaughter of a pig.  He then starts killing.

[Archivist]

Benny's Tape (1992).  About a dissociated teenage boy obscessed with a video showing the slaughter of a pig.  He then starts killing.

Doesn't sound like Benny's Tape/Video at all.  I saw that one years ago and while the themes and script were very haunting, it doesn't sound like the OP's description.  It's closer to Brainscan, IMO.