Michael John Anderson, 20, was convicted Tuesday night on all six counts, including first-degree murder, for shooting and killing Katherine Ann Olson, 24. He is scheduled to be sentenced this morning.
Prosecutors said Anderson simply wanted to kill someone when he posted an ad seeking a baby sitter in October 2007, according to The Associated Press.
When Olson showed up and then tried to leave, he pulled out his father's gun and shot her.
Olson's body was found stuffed into the trunk of her car at a nature preserve, according to the Savage, Minn., police.
Olson had traveled to Savage from her home in Minneapolis after responding to an ad for a nanny she'd seen posted on Craigslist, police said.
Olson's father, the Rev. Rolf Olson, told ABC News in 2007 that his daughter had found other nanny jobs, including one in Turkey, through Craigslist and had had positive experiences.
He described her as a warm, outgoing, "larger than life" person who loved theater. Olson said his daughter had traveled around much of the world, including Egypt and Argentina, where she worked as a juggler for a circus. Her e-mail address meant "crazy redhead" in Spanish, he said.
"She lived a larger-than-life existence for more than 24 years," Olson said. "I'm broken."
Olson wanted to go to Madrid to study in a graduate theater program and was considering the nanny job so she could make extra money for her trip, he said.
"Katherine was, unfortunately, too trusting," her father said. "She had found benefits on Craigslist, but in her trusting nature, she fell into this trap."
When Olson's best friend, Sarah Sevcik, last saw her the night before she disappeared, Olson was considering whether she wanted to work as an interpreter, Sevcik said. Olson ultimately decided the career wasn't for her.
Interpreters "really have to be silent and just relay information," Sevcik said. "But Katherine was somebody who needed to have a voice."