A 71-year-old described by prosecutors as a handyman pleaded guilty Friday to the murders of three women at the same apartment complex who had hired him for help, authorities said.

Kevin Gavin admitted to killing the three women between 2015 and 2021, the Brooklyn District Attorney’s Office said in a statement, which described Gavin as a “serial killer inside his own apartment building.”

Gavin pleaded guilty to one count of first-degree murder and three counts of second-degree murder in exchange for a sentence of 30 years to life in prison, the office said in a statement.

“This defendant exploited elderly women who trusted him, gained access to their homes, and murdered them in a series of brutal attacks that shocked the conscience,” District Attorney Eric Gonzalez said in the statement. “These victims were vulnerable neighbors who deserved safety and dignity, and instead had their lives stolen by someone they believed was there to help.”

The defendant’s lawyer had no comment.

Gavin lived at the New York City Housing Authority’s Carter G. Woodson Houses, a circa-1970 public housing complex for seniors in Brooklyn, where Myrtle McKinney, 82, Jacolia James, 83, and Juanita Caballero, 78, were killed in their apartments.

McKinney was stabbed in the neck with a knife on Nov. 8, 2015, the DA’s office said.

She had moved into the building more than 10 years prior as a retired housekeeper from Jamaica who had worked in Florida and the Bahamas, New York Magazine reported in an article about the killings.

James died after Gavin stomped on her neck and chest on April 30, 2019, the DA’s office said. It had previously said she was strangled.

A relative found James face down and bruised after pushing open her apartment’s unlocked door, the magazine reported.

Relatives described her as vigilant and wary of strangers, according to the publication, which reported she had lived in the complex for decades.

Caballero was strangled with a phone cord in her apartment on Jan. 14, 2021, the DA’s office. It has said the murder happened during a robbery.

Caballero, who was known as “Lucy” for her side hustle of selling loose cigarettes in the building, was found by her son, who was visiting for the weekend, New York Magazine reported.

The DA’s office said security video showed Gavin using her debit card a few days later. He was arrested a week after Caballero’s body was found, authorities said, and confessed to the three murders.

Gavin claimed to have been in disputes with each victim over money and that he “fought with each victim prior to their death,” the DA’s office previously said.

The killings inspired community concerns about security at the multistory complex in the Brownsville neighborhood, including what some said was a need for more security cameras. In early 2022, the housing authority announced that 127 security cameras had been installed in stairwells, on rooftops and in elevators at the two-building complex.

“Woodson Houses is now fully equipped with a new network of security cameras to help improve safety for residents,” it said.

Reached Friday, a spokesperson for the housing authority did not immediately provide a comment.

Gavin’s sentencing is scheduled for May 30.