For example, earlier this summer there was a report of a "woman whose dismembered body was found inside a suitcase and black plastic bag in a West Virginia creek [who] apparently was stabbed to death" (http://www.wjla.com/news/stories/0806/354752.html). This appears to be a classic case of attempted disposal of the evidence following a murder.
Another case, reported in 2005, was that of a Purdue University graduate student whose dismembered remains were found in a vehicle that has been abandoned in parking garage (http://www.findarticles.com/p/articles/mi_qn4155/is_20050901/ai_n15613591). In this case, the victim's wife was the prime suspect, as he was reported missing "the same day his wife was expected to plead guilty to injuring him in a stabbing last Christmas in their Lafayette, Ind., apartment." There is some international intrigue involved in this scenario, as the victim's wife apparently fled to China following the crime.
Mayhem has proven to be a shocking and depraved crime that has served such purposes as disposal of evidence, victim torture and sexual gratification of the perpetrator. As such, it is a severe aggravating factor when other crimes are present, as they often are.