A convicted online predator is serving a 105-year prison sentence for his role in an extortion scheme to produce child pornography, but officials are still on the lookout for hundreds of his victims.

FBI (Joe Raedle, Getty Images)

According to court testimony, 31- year-old Lucas Michael Chansler of Florida targeted 350 child victims domestically and internationally from 2007 to 2010, but just 109 have been identified. With that, the Federal Bureau of Investigations (FBI) has launched a campaign to gather any information from the public regarding the names and faces of Chansler's victims.

Chansler pleaded guilty in 2014 to nine counts of producing child pornography. He would befriend a young girl online and eventually ask her to expose herself. If she did, he would use the footage to blackmail the victim for more graphic photographs or videos. Chansler would inform the victim that if she did not comply, her original racy content would be shared online and with her friends and family.

Chansler used at least 135 different screen names while "sextorting" his victims, according to the FBI, and he had approximately 80,000 images and videos in his possession.

FBI
FBI

Celeste Danzi, a spokeswoman for the FBI Newark Field Office, said many of Chansler's female victims may feel too ashamed to come forward.

"We do want them to speak up to get closure and to be recognized for basically what's happened to them," Danzi said. "The shame is on the predator, not the young victims."

Danzi said the public can share information with the Bureau through the Newark office at (973) 792-3000, through the toll-free line (800) CALL-FBI, or online at fbi.gov.