Defensive mutilation, aggressive mutilation, offensive mutilation, and necromantic mutilation are are studied, and defined, within brutal murders. Normally, these mutilations are part of sex crimes.
Defensive mutilation is where one mutilates a body to the extent to which it cannot be identified. Aggressive mutilation takes place when a killer mutilates the genitals and face of the victim out of pure rage. Offensive mutilation, also known as lust murder, occurs when the murderer considers having intercourse with the victim once the victim is dead. Necromantic mutilation is where the murderer does desire to have intercourse with the corpse but takes "trophies" (removed body parts) in order to use the parts to complete sexual acts. Since both offensive and necromantic mutilation have sexual tendencies associated with the mutilation, they are considered acts of mutilmania (meaning one becomes aroused through mutilation).
One book which defines studies in mutilation is Forensic and Medico-Legal Aspects of Sexual Crimes and Unusual Sexual Practices (Anil Aggrawal). This book contains one section, page 363, which defines and describes a study (which took place in Sweden) regarding different types criminal mutilation.