Accused child killer Levi Aron pleaded guilty Thursday in a Brooklyn courtroom to abducting, killing and dismembering Leiby Kletzky, the 8-year-old boy who was kidnapped when he got lost walking home from day camp in Borough Park last July.

A visibly heavier Levi Aron answered questions from State Supreme Court Justice Neil Firetog in mostly one- or two-word responses. After he admitted Normal 0 false false false EN-US X-NONE X-NONE "smothering" Leiby with a towel, Firetog asked Aron what he did next.

"Got rid of the body," said Aron.

Aron's plea is a milestone in the gruesome and heartbreaking case, which gripped the city and rocked the tight-knit Orthodox Jewish community where both Aron and Kletzky lived. It also provides a measure of relief for Kletzky's devastated parents, who wanted to avoid the anguish of a trial, a family spokesman said.

State Assemblyman Dov Hikind, who represents the district that includes the Kletzky family's Hasidic community, read a statement from the parents in court Thursday.

"There is no way to comprehend the pain...our little boy Leiby was ruthlessly taken from us. Today we have received some partial closure. A day does not pass without thinking of Leiby... may our son's soul rest in peace and continue to advocate in heaven for all mankind," he read. 

"We want to thank DA Hynes for bringing this to a quick resolution... and not forcing us... to relive this. We are grateful to God for giving us Leiby and our other children. God did not abandon our son or our family for even one second."

The judge will sentence Kletzky to 40 years to life on Aug. 29.

NBC 4 New York first reported the anticipated guilty plea last week.

Brooklyn District Attorney Charles Hynes had pledged never to accept a plea in this case, but reversed himself because of the wishes of the family.

"Over several meetings with Mr. Kletzky, who is just an incredible human being, he convinced me that the family had suffered enough," Hynes said.

Aron previously pleaded not guilty. His lawyers still say he is mentally ill, but understands what he did.

"It's not something that inerfered with his ability to understand the nature and consequences of his actions," said Aron's lawyer, Jennifer McCann. "Which is why he [pleaded] guilty to a crime today."

Kletzky went missing July 11 of last year while walking home from religious day camp, the first time he was allowed to walk by himself. He missed his turn and got lost, and police say he approached Aron for help.

About two days later, the boy's severed feet were found in the freezer at Aron's apartment, along with bloody knives and a carving board. The rest of the boy's body was found in a red suitcase in a trash bin several blocks away. His legs had been cut from his torso.

According to prosecutors, Aron admitted he killed the boy after he panicked when he saw posters with the child's photo. After the two met on the street, Aron took the boy to a wedding upstate, then to his apartment.

Read a redacted transcript of his confession here.

The child remained at the apartment alone all day while Aron was at work. When Aron returned, he took a bath towel and smothered the boy, he said, according to authorities.

The medical examiner's office said the boy was given a cocktail of prescription drugs. But Aron's confession didn't mention that, and he denied ever tying up the boy, though marks were found on the child's body.

A court-ordered evaluation in August found Aron fit to stand trial on murder charges, but said he is deeply troubled, with an adjustment disorder and a personality disorder with schizoid features.

Get the latest from NBC 4 New York anytime, anywhere. Follow us on Twitter, Facebook and Google+. Get our apps here and sign up for email newsletters here. Get breaking news delivered right to your phone -- just text NYBREAKING to 639710. For more info, text HELP. To end, text STOP. Message and data rates may apply.