Former UN weapons inspector Scott Ritter has been found guilty of unlawful contact with a minor following an online sex sting operation.
Ritter, an outspoken critic of the war in Iraq, had a sexually graphic online chat in 2009 with an undercover police officer posing as a 15-year-old girl named Emily.
The 49-year-old was convicted on six of seven counts.
Ritter's lawyer said his client did not think he was speaking with a minor.
Ritter, a former US Marine, initiated a conversation through a Yahoo chatroom in February 2009 with police detective Ryan Venneman who was posing as the teenage girl.
Mr Ritter then performed a sex act on himself in front of a web camera, despite the officer's repeated claims that he was 15-years-old.
http://www.bbc.co.uk/news/world-us-canada-13089135
Note: 15 April 2011 Last updated at 02:00 GMT