serial killer book from the begining 2000's or end of 1990; agents chasing the killer against the clock and breaking into the apartment when they find a small mutilated body in the kitchen sink.

[Malcolm]

Hello
I am trying to find a book by an episode from the plot. It is a thriller book, probably from around the turn of the Millenium. The plot is about police or FBI agents hunting a serial killer in the USA. Probably it has a female protagonist, I mean female FBI agent or forensic or police detective. The episode I remember is about the team of the agents chasing the killer against the clock and breaking into the apartment when they find a small mutilated body in the kitchen sink. the body is very difficult to be identified, the team suspects it is an infant. It turns out to be a false call. The body belongs to the monkey, it was taken home by a biology teacher for research.
Does anyone have a clue?
I will greatly appreciate any help
Many thanks