A federal judge handed down a 30-year prison sentence Wednesday to a man who took pictures of himself sexually assaulting a 2-year-old girl, which he traded over the Internet for more child pornography.

Derek M. West, of Waipio, pleaded guilty in October to a single count of producing child pornography in a deal with federal prosecutors. He had been charged with three counts of producing and one of possessing child pornography.

U.S. District Judge Derrick K. Watson sentenced West to the maximum penalty allowed in the plea agreement.

“If it were up to me, it would have been north of that,” Watson said. He said the scar West inflicted on his victim is immeasurable and enduring.

Upon release from prison, West must register as a convicted sex offender and will be under court supervision for the rest of his life.

Honolulu police said when they searched West’s Samsung Galaxy S II smartphone in December 2014, they found it contained more than 480 images of child pornography. They were able to recover the images even after West had deleted them remotely from his desktop computer.

Assistant U.S. Attorney Lawrence Tong told Watson that more images were found on West’s desktop computer. He said 52 of the images were of the 2-year-old girl, which West used as currency to trade for more child pornography.

Tong recommended the maximum 30-year sentence because he said West’s deviant behavior had gotten him in trouble with the law before and that he is either unable or unwilling to control his impulses.

West said he apologizes to the people he hurt and hopes to one day earn their forgiveness.