Katherine Ann Olson was a 24 year old theatre and Hispanic studies graduate of St. Olaf College and a temporary nanny.
Katherine was killed on 25th October 2007 by 19 year old Michael John Anderson, in a Minneapolis, Minnesota suburb after seeing an ad for her services as a nanny on Craigslist.
The prosecution charged that Michael created and posted a fake advertisement on Craigslist "in order to lure women to his home so he might experience what it felt like to kill."
Posing as a married woman named "Amy" who was looking for nanny services, Michael exchanged emails with Katherine. When she arrived at his parents' house for an interview, he shot her in the back with a .357 Magnum and put her body into the trunk of her car. He then drove to Burnsville Nature Preserve, where he abandoned it. The car containing Katherine's body was discovered on 26th October, 2007.
Psychiatrists hired by the defence diagnosed Michael with Asperger syndrome, a form of autism. Michael's attorneys contended that the disorder played a key role in the shooting and explained Michael's behaviour after the shooting. The judge refused to allow evidence of the diagnosis to be presented in court, ruling there was no proof the disorder was connected to the crime and that it could invite jurors to speculate about diminished capacity, which is "not recognised in Minnesota."
Michael, who was the first murderer referred to by the media as a "Craigslist Killer", was found guilty of first degree murder and received a life sentence without parole on 1st April, 2009.
Alan Margoles, the lead attorney arguing in Michael's defence, stated that the killing of Katherine was "accidental" and that he plans an appeal because during the trial he had not been allowed to present evidence that Michael has Asperger syndrome. The Supreme Court of Minnesota affirmed the verdict and sentence on appeal in October 2014.