X Files YA #12 Grotesque

A serial killer is stalking the city, slashing his victims' faces before killing them. But when the murderer is caught, he claims to have been possessed by the spirit of an ancient, malicious gargoyle--one he fears will now possess someone else. When the brutal deaths continue, even after the alleged killer is safely jailed, Special Agent Mulder and Scully are called in. Is this the work of a copycat killer? Or could a demonic force somehow be responsible? Mulder can think of only one way to solve the case: In order to catch a monster, you've got to become one yourself...