CROMWELL, Conn. -- A 23-year-old Massachusetts woman is facing a sexual assault charge involving a 15-year-old Connecticut boy she met on the Internet.

Details of the investigation by Cromwell police were released Thursday. The affidavit contains details behind the arrest of Sarah Colby of Dennis, Mass., a few weeks ago.

Police said Colby and the boy met online through a friend of the victim. The arrest warrant showed the two began chatting through MySpace.com and MSN Messenger.

"Our investigation revealed they had exchanged correspondence and she understood that he was only 15 years old," said Cromwell Police Chief Anthony Salvatore.

Police said the online conversations eventually led to cell phone calls, trading nude photos and a sexual encounter at a motel in Cromwell.

Police learned of the relationship when the boy's mother discovered the two together the day after the motel rendezvous.

"Parents need to understand they need to monitor what their kid's doing," Salvatore said.

Colby was arrested in mid-August on charges of second-degree sexual assault and risk of injury to a minor. She is expected to appear at Middlesex Superior Court on Sept. 13.

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