Hillside Stranglers Case File: Kenneth Bianchi, Angelo Buono and the Victims

The linked California series ran from October 17, 1977 to February 1978: ten murders on nine separate nights, since two schoolgirls were taken together. Four victims were abducted in Hollywood, five in or around Glendale and one in the San Fernando Valley. All were killed at night, and the bodies were found on hillsides, roadside slopes and urban margins in an arc around Glendale.⁷

Karen Mandic, 22, and Diane Wilder, 27, both students at Western Washington University, were strangled in Bellingham on January 11, 1979. Bianchi had moved north in 1978 and was working as a security guard. He killed them alone. Bellingham police arrested him the next day.⁵¹

The name “Hillside Strangler” became official late in 1977, when the LAPD set up the Hillside Strangler Task Force, and it was singular. Some detectives already suspected more than one killer, because the scenes had no drag marks. An LAPD commander was quoted as saying there “may be as many as 4 or 5 sets of stranglers.”¹² Witnesses later described two men staging what looked like a police arrest.⁷ What investigators faced was a two-man partnership in which each killer could cover for, blame and conceal the other.

Washington prosecuted the Bellingham murders, and California prosecuted the Los Angeles murders. The two states negotiated a single plea agreement covering both. In exchange for his pleas, Bianchi was spared the death penalty, other charges were dismissed, and he was given the possibility of parole and a chance to serve his California sentence first, in California. That last benefit depended on his testifying fully and truthfully against Buono.²

Buono, 44 at the time of the murders by the Los Angeles Times’s count, ran a one-man auto-upholstery business out of the garage of his house at 703 East Colorado Street in Glendale and was “a sometime pimp.”¹²⁷ Bianchi later told investigators that nine of the ten Los Angeles victims were killed in that house.⁷ The prosecution tied the location to the crimes with fibers from the shop’s upholstery material and from a chair and carpet in the house, with Buono’s destruction of a gas pipe, and with Bianchi’s testimony. Buono was convicted of nine murders and sentenced to life without parole.⁷⁹

Bianchi had studied police science, been rejected by police forces and worked as a security guard.⁷⁵ In Los Angeles he posed as a psychologist, using forged diplomas built from the transcripts of a real psychologist named Steve Walker, which he obtained through a fake help-wanted advertisement.¹²¹⁵ Detectives called him “Slick Ken.”¹² He pleaded guilty to five California murders and the two Bellingham murders, and his testimony became central to Buono’s prosecution despite his repeated changes of story.¹¹⁴

The Washington Department of Corrections’ criminal history summary, quoted by the Washington Court of Appeals in 2022, describes the method this way: “The girls would often be picked up by Bianchi and Buono as a false vice arrest. The girls would then be transported to Angelo Buono’s business, and there they would be disrobed, raped by both Bianchi and Buono, and then strangled to death. All of their clothing would be thrown in the garbage container, and the bodies would then be transported from Buono’s business to the hillside area where they were subsequently found.”¹ Working as a pair made controlling a victim easier. It also meant each man’s only witness was his accomplice.

Labels such as “folie à deux,” “psychopath,” “dependent partner” or “dominant sadist” can be useful hypotheses, but they are no substitute for the legal record. Bianchi gave at least four versions of events involving Buono: sometimes the two men took turns strangling victims, sometimes he said he wasn’t there, and sometimes he said he watched Buono do it.¹⁴¹² The strongest analysis starts from conduct, roles, corroboration and the record of his changing accounts. For the clinical concept, see shared delusion (folie à deux).

Bianchi moved from Rochester, New York, to Los Angeles in January 1976, and Buono later said he had let his younger cousin stay with him briefly, as a favour to his aunt.⁵¹² After the arrests, it emerged that the two men had run pimping and pandering using teenage runaways from Arizona, in an outcall prostitution operation whose clients reportedly included prominent businessmen and a former police chief.⁷ Buono was charged with pimping and pandering, extortion and sodomy alongside the murders, and the judge severed those counts from the murder trial.⁵⁷ That history matters because the murders didn’t come out of nowhere: sexual coercion and economic exploitation of young women were already part of the partnership.

Bianchi kept trying for the status that comes with law enforcement. He took police-science courses, applied to police departments and worked security. In Bellingham he became a security company’s “patrol captain,” applied to be a reserve sheriff’s deputy and was taking police courses.⁷⁵ An aide to a Los Angeles County supervisor had given him a large official county seal that could be used for special parking and other privileges. Investigators also found plenty of evidence that both men had police badges.⁷ In the murders, false police authority was a practical tool: a badge and an “arrest” turned ordinary compliance into captivity.

A controlled location in Glendale gave the two men privacy, tools, time and distance from the dump sites. Bianchi testified that victims were placed in a particular chair and then assaulted and strangled on the bedroom floor.⁷ Separating the abduction, the assault and the disposal complicated the forensic picture: investigators were looking at bodies left on hillsides while the critical indoor scene was miles away, in a house Buono had cleaned so thoroughly that an April 1979 search found no fingerprints at all, not even his own.⁷

Later books and profiles often work backward from the murders, turning Bianchi’s adoption, childhood or personality into inevitability. This file does not. HistoryLink records that he was born in Rochester on May 22, 1951 and adopted that August.⁵ The evidence that counts here is behaviour: prior exploitation, deception, coercion, police impersonation, shared offending, and the physical record that later tied both men to the murders.

The first two victims, Yolanda Washington and 15-year-old Judith Miller, were taken from Hollywood streets where the killers could approach young women without immediately drawing attention, and contemporaneous accounts tie both to street prostitution.³⁷ That doesn’t make them responsible for the danger. It describes the environment the killers chose to exploit, and the pimping operation the two men themselves had run.⁷

Later victims included students, a waitress, an actress and two schoolgirls met in ordinary public places: a bus stop, a bus ride from a shopping mall, Bianchi’s own apartment complex, the street outside his building.¹²⁷¹⁷ The murders of Dolores Cepeda, 12, and Sonja Johnson, 14, ended any idea that the threat was confined to one adult subculture. Real panic began that November, when four victims were found in a single week.¹²

Terms such as “high-risk victim” can hide the actual mechanism. The useful question is which conditions the killers manipulated: public trust, transport, age, isolation, economic vulnerability, and the assumption that a badge meant safety. After Lauren Wagner’s murder, young women in Los Angeles grew afraid of submitting to police stops.⁷ The LAPD told its own officers not to chase women who ran from them.¹²

In his closing argument, Boren drew a circle around Glendale centred on the intersection of Glendale Avenue and Colorado Street. Within it, he showed, lay roughly every site where a body was found, each easy to reach from that intersection by major surface streets and the Golden State Freeway. Cindy Hudspeth was last seen at that intersection, and Buono’s home and shop were a block and a half away. A television reporter told Boren the case should have been called the “Glendale Strangler.”⁷

In a car-dependent city with many police jurisdictions, a series with this many scenes was hard to pull together. The LAPD handled seven crime scenes, the Sheriff’s Department two (Miller and Hudspeth), and Glendale police one (Kastin).⁷ In December 1982, Judge George took the jury out at night in sheriff’s vans, driving the route from each abduction site to Buono’s house and on to each dump site, usually two murders a night, with a court-ordered media caravan behind them.⁷

Leaving bodies in the open may reflect haste, access, practical disposal, contempt, a wish for them to be found, or several of these at once. The Los Angeles Times later wrote that the bodies were left “in ways that seemed designed to taunt police and maximize public terror,” and the 2002 obituary said Buono had arranged them.¹²⁴ The record supports the locations. Explaining why those places were chosen calls for more caution.

The two men posed as vice officers, flashed fake badges and used handcuffs.¹²⁷ The aim wasn’t theatre. Authority reduced resistance and caused confusion, and it let them turn a public encounter into controlled transport. Before the arrests, investigators already believed the killers were using some kind of police ruse.⁷

Bianchi told investigators about one aborted abduction before his plea. Investigators then found Catherine “Cathy” Lorre, daughter of the actor Peter Lorre, who described the same encounter: two men stopped her crossing near Hollywood Boulevard and Highland Avenue, showed police badges and asked for identification, then let her go. Bianchi gave inconsistent reasons, saying either that they saw a photo in her wallet of her on her father’s lap, or that it was something about her appearance. At trial, defence lawyer Gerald Chaleff undermined her general credibility, though Boren thought it “highly unlikely” she could have invented a story matching Bianchi’s.⁷

On the day Cindy Hudspeth was killed, Jan Simms, a grandmother driving north of the Ventura Freeway, saw a man gripping a young blonde woman by the wrists and pulling her toward a tan Excalibur or Excalibur-like sports car. Simms told the woman to get into her station wagon, and she did. The man said, “God will get you for this.” Simms later identified him as Bianchi and the driver as Buono. Her report became one of the task force’s 10,000 clues.⁷

Before trial, Judge George held a month-long hearing on hypnotized witnesses under the California Supreme Court’s new rule in People v. Shirley (1982). He found that Bianchi had faked being hypnotized and could testify. Beulah Stofer, who watched Lauren Wagner’s abduction and thought it looked like a police arrest, had not in fact been hypnotized and could testify. Others were excluded: Stofer’s neighbour, who saw two men transfer Wagner from her Mustang into a larger, dark car, and the defence lawyer Ronald LeMieux, who said he saw Yolanda Washington’s abduction.⁷

A woman who believes she is being detained by police faces an impossible choice, because resisting may feel dangerous or even criminal. Suspicion that the killer was a police officer was so widespread that LAPD Chief Daryl Gates told officers: “If a woman runs from you … don’t chase her. Understand that she may be panicking, thinking that you’re him.”¹² The case is also a study in how symbols of state authority can be exploited by offenders.

By early 1978 the Hillside Strangler Task Force had grown to 162 officers from the LAPD, the Sheriff’s Department and Glendale police, with a 24-hour tip line. Gates later wrote: “We had, in time, more than 10,000 clues, 4,800 parolees to check out, and 120,000 fingerprint cards to run for comparison.”¹² The problem was no longer a lack of information. It was deciding which information mattered.

“There was really no coordination whatsoever,” sheriff’s detective Frank Salerno told the Los Angeles Times in 2025. “Investigation by committee doesn’t work.” The LAPD’s new clue computer was haphazardly managed, and investigators spread across agencies did not reliably share what they had.¹² Under pressure, the LAPD arrested a Beverly Hills handyman on a jailhouse informant’s word, then released him three days later with a public apology from Gates.¹²

Bianchi’s name came up several times during the Los Angeles investigation (three times, by Boren’s count), and at one point he agreed to take a polygraph. No one followed up. “Our computer software could not collate all the information fed into it, and Bianchi’s name was spelled differently each time,” Gates wrote. “It continues to haunt me today that I didn’t personally go over every detail.”¹²⁷ The point is not that police “should have known” he was a killer from his personality, but that his fixation on authority kept placing him near the institutions he imitated.

The Los Angeles investigation didn’t crack because the task force finally found one decisive clue. Bellingham detectives arrested Bianchi for two new murders, saw his California driver’s licence and called Los Angeles. The address on it, 1950 Tamarind Avenue, was where Kimberly Martin had been abducted. Another of his former addresses was Kristina Weckler’s apartment complex, and a third victim had lived across the street.⁵¹²

Bianchi offered the two women $100 each, through Mandic, to guard a house in the secluded Edgemoor neighbourhood for two hours while its alarm system was repaired, and told them to keep it secret. The house, at 334 Bayside Road overlooking Chuckanut Bay, belonged to a retired executive who was away in Europe. Mandic told friends anyway, and named “Ken Bianchi” of Whatcom Security.⁵ The two women were killed on the night of January 11, 1979. At 4:30 p.m. the next day, a resident spotted Mandic’s green 1978 Mercury Bobcat at the end of Willow Court N, a wooded, undeveloped cul-de-sac. The two bodies were in the back seat.⁵

Bianchi’s employer reached him by phone, and he claimed he had been at a sheriff’s reserve-unit meeting and didn’t know Mandic. The reserve commander said Bianchi had asked to be excused from that meeting. Detectives took him into custody at a guard shack at the Port of Bellingham. His alibis were, in HistoryLink’s words, “so contradictory” that detectives believed they had their man. A witness had seen a man matching his description driving a Whatcom Security pickup in the area that night.⁵

The bodies were wrapped in clean sheets to preserve trace evidence, and the medical examiner, Dr. Robert P. Gibb, found that both women had been strangled with a ligature.⁵ At Bianchi’s 1979 plea hearing, Detective Duane Schenck testified to the corroborating forensics: the ligature autopsies, FBI fiber matches between the women’s clothing and the house, and Bianchi’s pubic hair on a victim’s outer clothing.¹

On January 13, Detective Fred Nolte called the Los Angeles County Sheriff’s Department about Bianchi’s California licence, and the call happened to be referred to Sgt. Frank Salerno of the task force. On Sunday, January 14, Salerno and his partner Dudley Varney arrived in Bellingham. A search of Bianchi’s house turned up property stolen from places he guarded, and a cache of jewelry. At least two pieces, a large turquoise ring and a gold ram’s-horn necklace, matched descriptions of jewelry worn by Hillside Strangler victims.⁵

Prosecution and defence jointly asked the court to seal the probable-cause affidavit because of speculation linking Bianchi to the Los Angeles murders. The trial court let The Bellingham Herald intervene to contest the sealing. On April 30, 1979, the Washington Supreme Court reversed, holding that “such intervention in a criminal proceeding is improper,” and that the paper’s remedy lay in a separate action.²³

Bianchi pleaded not guilty, then changed his plea to not guilty by reason of insanity in March 1979, when Washington announced it would seek the death penalty. He said he had no memory of the murders.¹⁵ Under hypnosis by the psychologist John G. Watkins on March 21–22, 1979, an alternate personality called “Steve” emerged, confessed to the Bellingham murders, talked about the Los Angeles killings and implicated Buono.¹⁶⁵ Watkins and Dr. Ralph Allison, who also hypnotized him, both concluded that he had multiple personality disorder.¹¹⁵

Judge Jack Kurtz appointed a panel of six to examine Bianchi. Two believed he had multiple personalities, two (both retained by the state) concluded he was faking both the hypnosis and the disorder, and two said they couldn’t be sure.⁵¹ All six found him competent to stand trial.¹

Martin T. Orne, the prosecution’s hypnosis expert, tested whether Bianchi would shape his symptoms to an examiner’s cues. He casually remarked, in Bianchi’s hearing, that true multiples rarely have only two personalities, then asked to speak to the part that was neither Ken nor Steve. A third personality, “Billy,” said it needed more time and emerged after a two-hour dinner break as “an enthusiastic, pleasant hustler.” Orne concluded that Bianchi was simulating both hypnosis and multiple personality, and diagnosed antisocial personality disorder with sexual sadism.¹⁵

Sheriff’s detectives found that Steve Walker was the name of a real psychologist. Bianchi had duped him into sending his school transcripts by placing a help-wanted advertisement in the Los Angeles Times for a fake therapy practice, then used them to forge credentials and pose as a psychologist. Detectives spent nearly two weeks at the newspaper’s microfiche machine before they found the ad. “Basically his multiple personality defense is destroyed,” detective Peter Finnigan said, “because your primary multiple personality isn’t yours, it’s a real person.”¹²

No jury ever ruled on the insanity defence. On October 19, 1979, after all six experts found him competent, Bianchi stipulated to his competency, withdrew the insanity plea and pleaded guilty to two counts of first-degree murder.¹⁵ The finding that he faked hypnosis came later, from Judge George, after a month-long pretrial hearing in Los Angeles.⁷ In 2022 the Washington Court of Appeals again rejected his claim that “hypnotic manipulation” produced his confession, holding that he had “failed to demonstrate that he was in fact in a state of hypnosis when he confessed.”¹

In Whatcom County Superior Court, Bianchi pleaded guilty to the first-degree murders of Karen Mandic and Diane Wilder. Prosecutor David McEachran withdrew his request for the death penalty, and Judge Kurtz imposed two consecutive life terms.⁵¹ Those terms carried the possibility of parole. In 1981, UPI calculated that he could not be considered for parole in Washington for 26 years and eight months.²²⁴

Flown to Los Angeles, Bianchi pleaded guilty before Superior Court Judge William B. Keen to five of the ten murders, one count of conspiracy to commit murder (and/or kidnapping or rape) and one count of sodomy. Keen imposed life terms that, under California law, merged. “I wish I had the power to have the sentences run consecutively,” he said.⁵¹ Under the joint agreement, he was not charged with the other five murders attributed to him and Buono.¹ Within about 30 minutes of the Los Angeles plea, the task force arrested Buono at 703 East Colorado Street. He was charged with 24 felonies, including ten murders, extortion, conspiracy, sodomy, and pimping and pandering.⁵

The benefit Bianchi wanted most was to serve his time in California, near treatment programmes unavailable in Washington. It depended on his testifying fully and truthfully against Buono.²¹ On January 9, 1984, after Buono’s trial, Judge George affirmed the prosecutor’s finding that Bianchi had not done so and sent him back to Washington. On February 1, 1984, California filed a detainer ensuring that if Washington ever released him, he would be handed over to finish his California life sentence. “Thus, both states would have to grant parole or clemency in order for Bianchi to be released from custody.”²

Before trial, Judge George granted a defence motion to sever the prostitution and sexual-assault counts. Bianchi, meanwhile, recanted, disowned his recantations and gave contradictory versions; at times he claimed he hadn’t been present at all.⁷¹² In a July 2 memo, prosecutors Roger Kelly and James Heins told District Attorney John Van de Kamp that Bianchi “would not be believable” and listed holes in all ten murder cases. One was a palm print on Cindy Hudspeth’s car that matched neither man. Another was that three people said they had seen Jane King alive after the date Bianchi gave for her murder.²⁵ On July 13 the district attorney moved to dismiss all ten murder counts and pursue only the pimping charges.²⁵¹² Kelly called it the “self-immolation” of Bianchi’s credibility.¹²

Judge George spent more than an hour reading aloud a 36-page ruling. Bianchi’s account was a “morass of contradictions,” he found, but there was a great deal of evidence to corroborate it that prosecutors had “glossed over,” including Catherine Lorre’s account and polyester fibers on two victims that matched material in Buono’s shop. He ordered the office to “vigorously and effectively resume” the prosecution or he would hand it to the attorney general. “Ten bodies don’t just get swept under the carpet!” he later told a reporter.¹² Van de Kamp declared a conflict of interest, and in August 1981 Attorney General George Deukmejian assigned deputies Roger Boren and Michael Nash, who told the court a two-week review showed Buono could be tried on all ten counts.⁷¹³

The defence argued that Bianchi had learned key facts from his own lawyers. The Court of Appeal noted that Bianchi “has told at least four different versions of the events” involving Buono, and had admitted that some of those changes came from information his attorneys gave him. It nonetheless blocked Buono from cross-examining him about his confidential conversations with the public defender, because Bianchi’s credibility was “already open to attack.”¹⁴ The only eyewitness who linked Buono to a victim was Markust Camden, who testified that he saw 15-year-old Judy Miller get into a Cadillac limousine driven by a man he identified as Buono. Katherine Mader later showed that Camden had been released from a mental hospital in Indiana two days before he identified Buono from photographs.⁷²⁰

The trial began on November 16, 1981, with an estimate that it would last a year. Jury selection alone took three and a half months. It ended on November 18, 1983, “two years and two days” later.⁷²⁰ The Los Angeles Times counts 729 days from jury selection to the nine guilty verdicts, with 392 witnesses and 1,807 exhibits.¹²⁴ Bianchi was on the witness stand for about six months (80 days, by UPI’s count), four of them under cross-examination.⁷⁹ The trial took place in the Criminal Courts Building in downtown Los Angeles, with other serial-murder trials running on the same 15th floor.⁷

The Wagner count was the strongest, and the jury’s first guilty verdict. Tape used to attach electrical wires to her palms had left adhesive on her wrists. Nylon and acrylic fibers clinging to it matched a particular chair in Buono’s house, and Bianchi had described putting victims in that chair. Buono’s purchase and later destruction of a flexible gas pipe showed consciousness of guilt and corroborated Bianchi’s account of trying to gas Kristina Weckler. In final argument, the defence suggested that whoever left Cindy Hudspeth’s car on the Angeles Crest Highway had walked out with a bicycle stowed in its back seat. Jurors spent a week studying photographs of the small Datsun before deciding that was improbable.⁷ The California Court of Appeal later called Bianchi’s testimony “abundantly corroborated.”²⁶

The jury found Buono not guilty of Yolanda Washington’s murder, the count with the “weakest evidence” in prosecutor Boren’s own words, where defence lawyer Gerald Chaleff said there was “no evidence … other than Mr. Bianchi.” Her mother, Catherine Campbell, said: “He will get whatever sentence he deserves eventually.”³ The jury convicted him of the other nine and, after about an hour, chose life without parole over death. “Not to impose the death penalty simply cheapens the lives of these girls,” Boren had argued.²² On January 9, 1984, Judge George imposed nine concurrent terms of life without parole. “I would not have the slightest reluctance to impose the death penalty. If there ever was a case for which the death penalty was appropriate, it is this case,” he said, adding that the killers had used “every form of legalized execution.”⁹⁵

Buono’s lawyers filed 1,300 pages of briefs. In November 1988 the Court of Appeal rejected his fair-trial challenge in a 29-page opinion by Justice Lynn D. Compton (no relation to Veronica Compton), finding Bianchi’s testimony “abundantly corroborated” by independent evidence sufficient by itself to support the conviction. It might seem improbable that anyone could be capable of such brutality, Compton wrote: “Yet it is certain that Bianchi and one other person were so capable. Once such a premise is accepted … the probability that (Buono) was that other person is an essentially inescapable conclusion.”²⁶

Buono was sent to Folsom Prison, where in 1986 he married for the fourth time. On September 21, 2002, aged 67, he died of a heart attack in his cell at Calipatria State Prison. Retired Bellingham detective Fred Nolte told CNN: “The world will probably [be] a better place without him. He will not be missed.”⁵⁴

Bianchi pleaded guilty to five California murders and the two Bellingham murders. In 1990 Washington set his minimum terms at 702 and 722 months, to run consecutively: 1,424 months in all. The board cited multiple victims, a high degree of sophistication and deliberate cruelty, and found that he represented “a very high risk for future dangerousness.”¹ In 2018 he refused a psychological evaluation, telling the evaluator his file was full of “garbage.” She scored him as meeting the criteria for psychopathy on the PCL-R. The board found him not parolable and added 120 months. In 2020 he attended with counsel, said he had earned several degrees and had had no serious infraction since 1996, and was again found not parolable.¹ He changed his name to Anthony D’Amato in 2023.⁶ He has filed more than a dozen petitions, and “no court has deemed any of his factual claims credible.”¹

The case’s lasting significance lies in multi-agency linkage, trace evidence, corroboration of an accomplice, forensic assessment of malingering, the admissibility of hypnotically refreshed testimony after People v. Shirley, and the question of what prosecutors should do when their essential witness is also a proven liar. District Attorney Van de Kamp later admitted that seeking dismissal “was an error,” and rivals used it against him in his 1990 run for governor.¹²⁷

Veronica Lyn Compton, 24, a self-described actress and playwright, wrote to Bianchi at the Los Angeles County Jail in June 1980, asking for help with a screenplay about a female serial killer. Between June and September they plotted to prove his innocence. She would fly to Bellingham, strangle a woman with white clothesline, and plant evidence to mimic the Mandic–Wilder murders. At their last meeting, Bianchi gave her a semen sample in the fingertip of a latex glove, hidden in the spine of a book, to leave on the victim’s body.⁵

In Bellingham, Compton befriended Kim Breed, 26, at a tavern and lured her to a room at the Shangri-La Downtown Motel with a promise of cocaine. She tied Breed’s hands and twice strangled her almost to unconsciousness. Breed, larger and unusually strong, struggled free and escaped. “I knew I was gonna die,” she later testified.⁵²⁹

Compton was arrested in Carson, California, on October 2, 1980. At trial, before a jury brought in from Pierce County, she claimed the attack was a publicity stunt and that Breed was in on it. On March 20, 1981, the jury convicted her of first-degree attempted murder, finding that she was armed with a deadly weapon, the ligature. On May 22, 1981, Judge Byron L. Swedberg sentenced her to life with the possibility of parole.⁵²⁸ She escaped in 1988, was recaptured nine days later, and was paroled in 2003.⁵