Ezell Channel, 36, was arrested Thursday at the studio's parking lot and charged with two felonies.
The mother of the victim, a teenage boy, became suspicious of Channel when he began spending time with her son, said city police department Sgt. Jay Jette. She later checked his name on the state's Megan's Law Web site and found he was a registered sex offender with a listing for "lewd or lascivious acts with child under 14 years."
A subsequent investigation found allegations that Channel had fondled the teenager, Jette said.
Channel was a freelance, temporary employee at the studio, which specializes in children's programs, Jette said. Nickelodeon issued a statement Friday saying it was cooperating with the police investigation but had no further comment.
Channel is being held on $500,000 bail and is scheduled to be arraigned Monday.
