A man who filmed himself sexually assaulting young Asian girls pleaded guilty Tuesday to child pornography charges.

William Constable, 54, a self-employed contractor, was arrested in October when he tried to retrieve a camera he left in a Cape Cod hotel room. A hotel employee who found the camera called police after seeing images of a man having sex with young girls.

Prosecutors said the camera and dozens of cassettes and compact discs later seized from Constable's Nantucket home showed him sexually assaulting girls as young as 5, sometimes two at a time.

During a hearing in U.S. District Court, Constable pleaded guilty to seven counts of sexual exploitation of children and one count of possession of child pornography. According to a plea agreement filed with the court, the recommended sentence will be 25 years in prison and a $50,000 fine, with restitution to be determined when Constable is sentenced on June 10. He also faces lifetime supervision after his release.