(AP) - A woman who responded to an online request for a babysitter told her roommate that the person who placed the ad "seemed kind of strange."
Katherine Ann Olson went anyway, thinking she would be meeting a woman named Amy, or a couple. Instead, authorities say, she was lured to the home of her killer, who shot her in the back before stuffing her in the trunk of her car.
On Tuesday, prosecutors charged Michael John Anderson, 19, of Savage, with second-degree murder. Their evidence: blood spatters in the suburban home he shared with his parents, a gun in his bedroom and drag marks on the stairway.
Olson's body was found Friday in the trunk of her car, which was abandoned in a park about five blocks from Anderson's house. Her ankles were bound with red twine, according to the criminal complaint filed in Scott County.
Her purse, her smashed cell phone, and bloody towels - one of which bore Anderson's name - were found in a garbage can nearby.
"The life of a bright, promising young woman has been taken for absolutely no reason," said Scott County Attorney Pat Ciliberto. "The evidence is that this woman was lured to the defendant's house and was shot."
Ciliberto said the evidence indicates Olson and Anderson did not know each other. He also said there was no evidence of sexual assault.
Attorneys for Anderson had no comment on the charge.
"I think in a case like this, we'll just let the judicial process take its course," said Robert M. Speeter, a defense attorney.
According to the criminal complaint, Olson, 24, went to Anderson's home Thursday for a baby-sitting job she had seen advertised on Craigslist, a popular Internet bulletin board. Olson had taken nanny jobs at least twice before, including a job in Turkey, after answering online ads.
This ad was posted by someone claiming to be "Amy." Olson's roommate, Matt Thiede, told police that Olson had talked with "Amy" and commented that "the woman seemed kind of strange."
Olson and "Amy" exchanged e-mails, and in one message, "Amy" asked Olson to baby-sit a child between 10:30 a.m. and 5 p.m. on Thursday.
The address and phone number provided to Olson matched Anderson's address and cell phone number, authorities said.
Ciliberto said it appears Olson thought she was responding to a woman or a couple in need of babysitting. The evidence, he said, shows that the e-mail account with the name Amy was "one and the same with Michael John Anderson."
Olson was last seen Thursday morning at her apartment, but she never returned.
Authorities began investigating Friday morning after Olson's purse was found in a garbage can in Savage.
Their investigation led them to the house where Anderson lives with his parents. Police found blood spatters in several locations at the home, including on the stairs.
In Anderson's bedroom, authorities found a gun and shell casing, as well as blood on the walls and on the mattress, the criminal complaint said.
A neighbor saw Olson's car sitting in front of Anderson's house for more than two hours Thursday, the complaint said.
Anderson was arrested at Minneapolis-St. Paul International Airport, where he fuels planes. He has been in the Scott County Jail since his arrest late Friday. His bail was set at $1 million.
Anderson first told police he had nothing to do with the murder, and denied having phone contact with Olson. But cell phone records indicated Olson called Anderson Thursday morning, the court documents said.
He also said he hadn't used Craigslist since January, though the e-mail address in the ad matched his address. He told police his mother and three friends had access to the account.
When confronted with the evidence, Anderson changed his story, according to the complaint; he said he was present during Olson's slaying but the killing was committed by a friend who "thought it would be funny."
Olson was a 2002 graduate of Park High School in Cottage Grove, where she was co-valedictorian. She graduated from St. Olaf College in 2006.
Her family posted a letter on Facebook, saying that Olson had used Craigslist in the past to find "kindred spirits and opportunities."
The family letter also said Olson loved children, and was involved in the church choir, a women's group and numerous outreach activities.
Susan MacTavish Best, a spokeswoman for Craigslist, said Olson's slaying is the first the company has seen in its 12-year history.
She said it's important for people to be cautious "whether you're responding to an ad in your local weekly newspaper, your gym notice board or on an online bulletin board."
"Random acts of violence such as this cannot necessarily be known from what appears to be an honest ad," she said in an e-mail.
Still, there is a risk. In California, a 19-year-old college student went missing in June after she met a convicted sex offender on Craigslist.
In Philadelphia, a man was accused of raping seven women, six of whom he met on the dating site Match.com. He was convicted this summer of two counts of sexual assault but acquitted of other rapes.
(Copyright 2007 by The Associated Press. All Rights Reserved.)