It’s probably gonna make it a little harder but I saw this movie around 2009 on a hungarian tv channel that usually features older movies, so I presume the movie was made somewhere around the 90s or possibly in the early 2000s.
It was a horror movie about a serial killer that was somehow put together from other, deceased serial killers’ body parts. There was a female and a male detective investigating the case and the final showdown was in a dark cellar. The killer himself had a mangled face covered with wounds. Unfortunately I don’t remember much else but I specifically remember that the detectives thought they were looking a copycat but somehow they figured out that something supernatural was going on and it was actually not one specific person but one created from the parts of other killers. It is not the movie called ‘Body Parts’ even though the plot is similar to some extent.