PORTLAND – A Sanford man faces up to 10 years in federal prison after pleading guilty to possession of child pornography.

Timothy Stevens, 40, pleaded guilty Tuesday in U.S. District Court, Assistant U.S. Attorney Toby Dilworth said.

Stevens was indicted last summer after his girlfriend tipped police about material she found in his computer. Police say he had thousands of pornographic pictures of children on computer disks.

Police said the images were downloaded from the Internet and did not depict local children.

Stevens is now serving the remaining two years of a sentence for his 1992 conviction on two counts of unlawful sexual contact with a boy under 14 years old. He admitted a year ago to probation violations and was sent to the Maine Correctional Center in Windham, Dilworth said.