‘He Was An Easy Guy To Get With The Program’ — Who Was ‘Hillside Strangler’ Angelo Buono?

The Hillside Strangler was a unique case, as it turned out the strangler was actually a pair of murderous adoptive cousins.

Kenneth Bianchi and Angelo Buono impersonated off-duty police officers to lure victims to their death in the late 1970s.  Los Angeles residents were gripped with fear after women were discovered strangled and discarded in the hills surrounding the city.

In all, 10 women and girls were murdered during the California spree — although Bianchi killed another two victims on his own in Washington state — before the pair were arrested.

“The Hillside Strangler: Devil in Disguise,” a new four-part Peacock docu-series, offers an in-depth peek inside the minds of the cousins. It particularly focuses on Bianchi, who is thought to be the mastermind behind the killings. But what about Buono?

Buono, like his cousin, was born and raised in Rochester in upstate New York. When he was younger, he was allegedly violent and had an affinity for beating people up and stealing — at least, according to Bianchi. Buono was also said to claim he was a member of the Mafia.

He moved out to California first, and Bianchi later followed when he was in his 20s. Bianchi’s mom arranged for him to live with his older cousin in Glendale; Buono was over 40 by that point. Buono had found work in L.A. He owned a car upholstery shop, and his house was located in front of the business.

Buono had married a woman named Mary Castillo, but they divorced before he embarked on his serial killer spree, The Orange County Register reported in 2007.

Bianchi’s former girlfriend Sheryl Kellison tells producers Buono “wasn’t friendly.”

“He was very cold and he did not talk very much at all,” she reflects, adding that he was “gruff” and “abrupt.”

“He just seemed very mad at the world,” she says.

Buono also apparently referred to himself as “The Italian Stallion,” as he liked to be thought of as a ladies’ man. Kellison notes that there were often a lot of girls at the house; Buono claimed they were his daughter’s friends. After Ken Bianchi was arrested in early 1979, two women alleged they were being sex trafficked out of the house. 

Buono was arrested after Bianchi told investigators and psychiatrists Buono was a participant in the killings.

In footage obtained by “The Hillside Strangler,” Bianchi tells investigators that Buono “was just an easy guy to get with the program."   

By program, Bianchi meant killing people.

Buono was sentenced to life in prison in 1983 after being found guilty of nine of the murders, The New York Times reported. He died alone in his cell in the California State Prison at Calipatria in September 2002 at the age of 67, the Washington Post reported at the time. He had a heart ailment at the time of his death and there was no sign of trauma when he died.

''He had assigned duties at the prison, and he was single-celled because of the nature of his crime,'' Bob Martinez, a spokesman for the Department of Corrections, told The New York Times in 2002. ''There was nothing exceptional about his conduct in prison.''

Misfortune would follow the family: In 2007, Buono’s then-20-year-old grandson Christopher Buono shot Buono’s former wife, Mary Castillo, in an Orange County storage space before dying by suicide in an office, the Orange County Register reported.

For more on this case, watch “The Hillside Strangler: Devil In Disguise,” streaming now on Peacock.