MISSOULA, Mont. -

A Missoula man is in jail on $100,000 bail after prosecutors say he arranged to have sex with an underage girl.

Police arrested James Scott Richey, 41, after a month long investigation.

Richey allegedly put an ad on Craigslist looking for a sexual encounter. Undercover law enforcement set up Richey to meet, who he believed to be a 14-year-old girl, at a park. That's where Missoula Police arrested him.

He's charged with sexual abuse of children.