A Los Angeles school teacher has pleaded guilty to a series of heinous abuses against his students, including blindfolding them and feeding them cookies laced with his semen.

Elementary school teacher Mark Berndt pleaded guilty on Friday to abusing 30 students at Miramonte Elementary School for the last two decades. Berndt was caught after a photo technician reported dozens of blindfolded third graders in photographs he was developing for Berndt. When investigators searched Berndt's classroom, they found semen on a spoon in a trash bin. Berndt had been feeding his students cookies laced with his own semen.

After being removed from the classroom in 2011, Berndt was paid $40,000 by the school district to drop the appeal of his suspension. The school district has already settled 63 cases relating to the abuse, with 71 still pending.

The guilty plea calls for Berndt to spend 25 years in prison.

"He's going to jail essentially for the rest of his life," the attorney for the students and their parents told the Associated Press. "You can't ask for more than that."

The school district had received reports of Berndt abusing students since the 1990s, but did not act until the the police intervened.