A Norcross man, a registered sex offender, was sentenced to life in prison without parole Friday after he was convicted of molesting a 13-year-old girl.

The jury acquitted David Christopher Roberts, 43, of rape and false imprisonment, said Cobb County District Attorney Vic Reynolds, but it convicted him of aggravated child molestation, enticing a minor for indecent purposes and four counts of child molestation.

Cobb Senior Judge G. Conley Ingram immediately sentenced Roberts as a recidivist to life in prison without the possibility of parole, Reynolds said.

Roberts met the victim through a phone chat line, and late in the evening of August 6, 2012, he drove to Cobb County to meet her, Reynolds said in an email. The molestation happened on the playground at Pitner Elementary, on Wade Green Road in north Cobb.

Roberts was previously convicted of raping a teenage girl in Indiana in 1992. He also has two felony drug convictions.

“This man is clearly dangerous,” said Assistant District Attorney Susan Treadaway, who prosecuted the case. “The jury’s verdict secured a sentence that provides our community the peace of mind of knowing he will never have the opportunity to harm another child.”