A Baton Rouge man has been convicted in the extortion of numerous children he is accused of using to produce and receive child pornography, the U.S. Attorney’s Office in Baton Rouge reported Thursday.

Matthew Chaney Walker, 25, told officials that in 2014 he met young girls online and pretended to be a teenage girl using different online account names, U.S. Attorney Walt Green said in a release. While chatting with the girls online, he suggested that they trade sexually explicit photos. He initiated the trade by sending an explicit photo of a girl he pretended to be.

After receiving compromising photos in return from the girls, he demanded more suggestive photos and threatening to show the initial photos to the victims’ families and friends if the girls did not comply, the release says.

Walker pleaded guilty to four counts of extortion, three counts of production of child pornography and three counts of receipt of child pornography. Walker will be sentenced May 5.

Assistant U.S. Attorney Cam T. Le is prosecuting the case.

The investigation is ongoing as law enforcement attempts to identify more victims, the release says. Anyone who believes they may have been a victim of Walker’s actions can contact the Baton Rouge Office of the U.S. Department of Homeland Security at (225) 757-7770, ext. 106.