A Seminole County man pleaded guilty Thursday in the first child-pornography case filed by the state attorney general's CyberCrime Unit, a spokeswoman said.

Monrovia McKenzie, 42, faces up to 120 years in prison after placing pornographic videos on the Internet.

Undercover members of the unit traced them back to him and used a search warrant to seize more than 500 digital images and videos from his computers. He was arrested in March 2006.