By SCOTT HARRISON

s.harrison@krdo.com

LONGMONT - A convicted sex offender who had failed to register with authorities was caught after a mother found he was exchanging E-mail messages with her daughter on MySpace. 

"My daughter first came to me and told me that she was talking to someone, and it was starting to make her feel uncomfortable," explained the mother, who wishes to remain anonymous.  She said she began checking for phone numbers, then decided to check the state's sex offender list.  "When I saw his name and face pop up, that was the worst."

Police arrested Andrew Coslett, 30, who has served time for attempted sexual assault on a child on 2000.  Tim Lewis of the Longmont Police Department praises the mother for being alert, getting involved and contacting them.  "She prevented something much more tragic from happening.  We looked into it and found (Coslett) had not registered; that he was working on the Internet--and that was a violation of state law."

The mother said she discussed the experience with her daughter.  "When I showed her his photograph and there it was as a sex offender, she started to cry."

Police say Coslett also has previous arrests for aggravated vehicle theft, burglary, forgery and fraud.  They also will investigate whether he had communicated with other children.