CENTENNIAL, Colo. — A 32-year-old man convicted of using his youthful looks to befriend and sexually assault teens was sentenced to 508 years in prison Monday.

Authorities said Zuri-Kye McGhee targeted 18 boys and one girl between ages 13 and 15. His 54-year-old mother is accused of helping him in some cases by introducing him to families with young children, and she is scheduled to stand trial in February.

He was convicted in August of 63 counts, including sexual assault on a child with a pattern of abuse. McGhee’s attorney, deputy public defender James O’Connor, did not immediately return a call.

“The district attorney’s office is very pleased with this sentence, as our goal was to keep Mr. McGhee away from children for the rest of his life,” district attorney’s spokeswoman Kathleen Walsh said.

Walsh said the judge also ordered McGhee, who lived in the Denver suburb of Aurora, to pay $9,556 in restitution and designated him a sexually violent predator.