Help with a movie title (From 90's I guess)

I've been searching for this movie for years! I've posted on some forums but no luck.

Apparently it's a TV movie from 90's because it must be earlier than 2000. I think i saw it between 1994 and 1999, HBO channel probably.

Well, the movie is about a serial killer that was doing some crimes, so a detective is investigating those crimes and at some point he realized that there isn't just a guy (actually they were 4 guys). So the detective was hunting one by one, (I guess one of them commit suicide to avoid caught).
The last minutes of the movie shows that case was closed with 4 killers caught, but while detective is talking, a homemade video of the 4 killers is shown, when they were kids and they all were together, suddently video stops in a mirror and shows a 5th guy, the one holding the camera and who wasn't captured.

So, the clues i got are:
Crime movie with a serial killer.
Detective realized that the killer was actually 4 friends. (plus one missing).
Apparently a TV movie (Not for cinema)

And the most important thing, the movie was in TWO PARTS. Part 1 ends with "to be continued..." and the real end is in the second part.

I hope someone can help me with this title, I really would like to watch it again.

So if you don't remember the title, but can contribute with another detail, scene or an actor, please do it.

Thanks in advance.
Adri.