Federal law enforcement officials arrested an aide to Sen. Maria Cantwell (D-Wash.) on Friday after the 28-year-old staffer allegedly attempted to have sex with what he thought was a 13-year-old boy, according to federal court records.

The records, which were posted by The Smoking Gun Web site on Monday, indicate that the FBI arrested Cantwell scheduler Mike McHaney on Friday after a cooperating witness helped set up a sham meeting between McHaney and what he thought was an underaged boy.

According to the documents, it appears that McHaney set up the lunchtime meeting during an AOL chat session during work hours, although it is unclear whether he was using Senate computers at the time.

An aide to Cantwell could not be reached for comment at press time. The Smoking Gun reported that “a caller to Cantwell’s office was told late [Monday] that, as of last Friday, McHaney no longer worked for” Cantwell.

This is the third sex scandal to hit the Senate this year. Earlier this session, Sen. David Vitter (R-La.) became embroiled in the “D.C. Madam” prostitution scandal, while this summer, Sen. Larry Craig (R-Idaho) was arrested in a Minneapolis airport men’s restroom during a public sex sting. — John Stanton