A registered Maine sex offender who used the wireless network at the Bangor Public Library last year to upload child pornography from his phone to the Internet was sentenced on Monday to serve 12 years and one month in federal prison.

Joshua Dunston, 38, who resided most recently in Bangor, was also sentenced by Judge John Woodcock Jr. in U.S. District Court in Bangor to serve the remainder of his life on supervised release after completion of his prison term and to pay $13,000 in restitution.

At the time of Dunston’s arrest on the charge of possession of child pornography, he was already on supervised release for a 2006 conviction on another federal charge of possession of child pornography. He was also previously convicted in 2003 on Maine state charges of possession of sexually explicit material of a child under 16 and sexual abuse of a minor, according to the Maine Sex Offender Registry. The registry lists Dunston as a resident of Ellsworth.

In the new case, Dunston uploaded multiple images of child pornography to online accounts that he controlled between March 17 and May 5, 2015, and kept many more images of young children being sexually abused on his phone, according to a prosecution document filed with the court.

“The defendant confirmed to law enforcement that he used his phone to download images from the Internet, either from social media sites or using file-sharing programs. In seeking out these images, the defendant was looking specifically for images involving the sexual exploitation of pubescent and pre-pubescent females,” Assistant U.S. Attorney Chris Ruge wrote in the prosecution document.

Dunston pleaded guilty to the possession of child pornography charge last Oct. 29.