A man was arrested on child porn charges after pawning a laptop computer that contained photos of him engaged in sexual conduct with a 5-year-old girl, federal prosecutors said Tuesday.

The owner of the pawn shop contacted police after the images were discovered.

Brian Dotson, 45, of Bel Air was identified as the man in the pictures, in part through a cartoon-character tattoo on his left bicep, the U.S. attorney's office said.

He could get up to 30 years in prison on the federal child pornography charges. He was also charged in state court with rape and sexual abuse.

Investigators contacted the girl's parents, who said she had been to Dotson's apartment several times, prosecutors said.