(AP) - Anthony Weiner has begun his 21-month prison sentence for illicit online contact with a 15-year-old girl.

A Bureau of Prisons spokesperson confirmed Monday that Weiner has reported to the Federal Medical Center Devens in Massachusetts.

The facility is in Ayer, about 40 miles west of Boston. It has more than 1,000 inmates at the medical center and over 100 more at an adjacent minimum security satellite camp.

It's the same facility that once housed Boston Marathon bomber Dzhokhar Tsarnaev.

Weiner was sentenced in September by a judge who said Weiner's crime resulted from a "very strong compulsion." A tearful Weiner said he was undergoing therapy and had been "a very sick man for a very long time."