A co-founder of Atlanta’s annual science-fiction convention was arrested Tuesday for allegedly taking a picture of a girl in a doctor’s office, according to police.

Ed Kramer, 57, is already on probation for molesting three boys. He was convicted of child molestation in 2013 and is designated by the state of Georgia as a “sexually dangerous predator.”

Kramer, who is no longer affiliated with the DragonCon convention, pleaded guilty to three counts of child molestation 13 years after his original indictment by a Gwinnett County grand jury. His trial was delayed due to his medical conditions.

Under the plea agreement, Kramer was sentenced to 20 years, with the first 34 months to be served under home confinement at his Duluth-area home. The remainder of Kramer's sentence was to be served on probation.

According to Lawrenceville police, Kramer allegedly took a 7-year-old’s picture without her parents’ permission. He was being held Tuesday night at the Gwinnett jail.

Fans of everything nerd in the thousands descended on downtown Atlanta for DragonCon 2018!