A Henrietta man has pleaded guilty to production of child pornography, federal prosecutors say.Mark Buechler previously pleaded guilty to sexually abusing two boys.Investigators executed search warrants at Buechler's Henrietta home on two occasions. The FBI was subsequently contacted, and a federal search warrant to examine digital and storage devices seized during these instances was secured. Federal investigators found nearly 8,700 images of child pornography, as well as two videos.Buechler will be sentenced to 20 years in prison in January for the state charges he faced. He will be sentenced on federal charges in March; for those, he faces 15 to 60 years in prison.