Regular necrophilia refers to the sexually motivated abuse of corpses and is not considered as severe crime in many western countries. However, the risk of "switching" to necrophilic homicides, i.e., committing a homicide to obtain a dead body, has to be assessed by forensic experts. We present a case of semi-professional dissection, preservation and sexual abuse of the body and body parts of a 14-year-old girl. Every step was documented by the offender on thousands of digital images thus allowing an exact reconstruction of necrophilic acts and fantasies. Three months after the disappearance of the body the remains could be recovered and linked to the deceased by pathological examination and DNA analysis. The offender had excessively used the internet for downloading files with sadistic and necrophilic contents including autopsy instructions. The psychiatric examination of the socially integrated and married patient revealed a severe personality disorder. Two other, previously unsolved cases could be attributed to him showing a clear progression of fantasies and acts.