Murder of Katherine Ann Olson

Katherine Ann Olson (born September 16, 1983) was a theater and Hispanic studies graduate of St. Olaf College who was working as a temporary nanny. In October 2007, she responded to a Craigslist advertisement seeking nanny services, posted by someone using the name "Amy." Olson exchanged emails with "Amy" to arrange an interview.

The advertisement had in fact been created by Michael John Anderson, then 19 years old, of Savage, Minnesota. Prosecutors charged that Anderson posted the fake ad specifically "in order to lure a woman to his home so he might experience what it felt like to kill." When Olson arrived at Anderson's parents' house on October 25, 2007, for the purported nanny interview, Anderson shot her in the back with a .357 Magnum. He then placed her body in the trunk of her own car and drove to the Burnsville Nature Preserve, where he abandoned the vehicle. Olson's car, with her body inside, was discovered on October 26, 2007.

Because Anderson had located his victim through Craigslist, media outlets labeled him a "Craigslist Killer," a term subsequently applied generically to other offenders who used the classified-ads website to find victims; Anderson was reportedly the first person given this label in news coverage.

At trial, psychiatrists retained by Anderson's defense diagnosed him with Asperger syndrome, a form of autism, and his attorneys argued the condition was central to explaining both the shooting and his conduct afterward. The presiding judge declined to allow evidence of the diagnosis to be presented to the jury, ruling that no proof connected the disorder to the crime and that admitting it risked inviting jurors to speculate about diminished capacity, a legal concept "not recognized in Minnesota."

Anderson was found guilty of first-degree murder. On April 1, 2009, he was sentenced to life in prison without the possibility of parole. His lead defense attorney, Alan Margoles, characterized the killing as "accidental" and announced plans to appeal on the grounds that the Asperger syndrome evidence had been improperly excluded. The Minnesota Supreme Court reviewed the case and affirmed both the conviction and the sentence in October 2014. Anderson is incarcerated at Oak Park Heights prison in Minnesota.