A sixth New Jersey federal prison inmate serving a sentence for trafficking in child pornography has admitted possessing and distributing child sex abuse videos inside the prison.

Prosecutors say Christopher Roffler pleaded guilty Wednesday. The 30-year-old Virginia Beach, Virginia, man will be sentenced in August and faces at least 10 years in prison, a term he would serve after his current sentence is completed.

Prosecutors say Roffler was among several Fort Dix inmates who used contraband cellphones and removable storage cards to share child porn. Five other inmates have pleaded guilty. Charges are pending against two others.

Roffler admitted having a memory card with 305 videos and 16 images of child porn, some of which depicted prepubescent children. He also admitted using a smartphone to view and possess child porn.