A San Diego pediatric nurse was sentenced to 80 years in prison for performing sex acts on two newborns and videotaping them. During the sentencing, the judge said the nurse was "the worst of the worst."

Michael William Lutts, 50, a former nurse, pleaded guilty in January to two counts of sexual exploitation of a child and one count of distribution of child pornography. He admitted to 15 instances of photographing or videotaping the infants in "sexually explicit situations at both his home and his work place," the U.S. attorney said.

U.S. District Judge John Houston said Lutts was "the worst of the worst" and described what he had done to the two-month-old premature boy and 11-month-old girl "worse than a mass murderer shooting 20 people" because the victims were fragile and easy to victimize.

“This defendant is a parent’s worst nightmare and a predator to society. He should never see the light of day," said Assistant U.S. Attorney Alessandra Serano, asking for a sentence of 65 years. "Rehabilitation would be futile.”

As part of his plea agreement, he will not be able to appeal his sentence.

Judge Houston said he would not recommend any mental health treatment because the "taxpayers shouldn't waste their money on (his) treatment." Houston said he handed down the sentence, giving the man 15 more years than asked for by the prosecution, because he wanted to "send a message to others who conduct this activity under the cover of dark."

A federal grand jury indictment says around July 24, 2014, he took sexually explicit digital photos of an 11-month-old girl.

He then began performing lewd acts on his prematurely born, 2-month-old foster child on Aug. 4, 2014, the day Lutts received custody of him, officials say.

Investigators detail graphic incidents in court documents, alleging Lutts touched and manipulated the infant’s genitals while masturbating and filming the abuse.

Pictures show the hospital tag was still attached to the boy’s leg, according to a complaint. The FBI says the baby can be heard crying through many of the videos.

Agents started tracking Lutts because they believed he was a child pornography distributor. When they served a search warrant to his house, they say they found several hundred pornographic images and videos involving children. Lutts also agreed to give up his College area home, in which many of the crimes took place.

The foster child has since been placed in the care of Child Protective Services.

Kaiser Permanente said Lutts was terminated in September 2014.

Two other men are accused of conspiring with Lutts. A federal indictment says Stephen Schaffner, an ex-counselor, directed Lutts to sexually abuse his foster child and send pictures to him. Bartolomeo Baravella was also arrested on suspicion of planning to kidnap a baby with Lutts. Baravella has been charged with possession of images of minors engaged in sexually explicit conduct.