Police said Baumgartner was driving his Ford F-150 truck with an Alberta license plate when he was arrested.
Steven Munz, a close friend of Baumgartner, had said that Baumgartner had been on the job for only three months and wanted to eventually become a police officer, but said Baumgartner didn't believe he had what it took. Munz said he had noticed a change in his personality in the last year, and that he had been irrational at times.
In a profile on the dating website Plenty of Fish, Baumgartner bills himself as an armored car guard interested in video gaming. A photo shows him shirtless holding a cell phone. He says he has a laid back personality and a "10" physique.
"I'm a great guy. We don't come around often," he writes.
But his Facebook page is much darker, quoting the character of the anarchist Joker from the movie "Dark Knight" and musing about "popping people off."
Baumgartner lived with his mother and step-sister in Sherwood Park, a bedroom community just east of Edmonton.
Associated Press Writer Rob Gillies in Toronto contributed to this report.