UPDATE (Dec. 6, 9:49 p.m. PT) — In a unanimous decision Thursday, the Oregon Supreme Court tossed out several 2015 murder confessions because of the way Portland Police Bureau detectives conducted their interviews involving a defendant with mental illness.

The opinion could shape the way police agencies in the state conduct interrogations going forward, especially using techniques where law enforcement officers lie to defendants about the strength of the case against them.

The justices noted officers went too far in this case, but also said it was a “close case.”

“Viewed independently, none of those factors would be dispositive, but together they indicate that the detectives’ methods and inducements may have persuaded defendant to tell the detectives what they wanted to hear, whether or not that was the truth,” the court ruled.

Homer Lee Jackson is charged with 12 counts of aggravated murder. In October 2015, Portland police detectives interviewed him over the course of two days in connection with four murders from the 1980s. All the victims were believed to be engaged in prostitution in North Portland.

This image provided by the Multnomah County Sheriff's Office shows Homer Lee Jackson, who is accused of killing four women who were working as sex workers in the 1980s.

This image provided by the Multnomah County Sheriff’s Office shows Homer Lee Jackson, who is accused of killing four women who were working as sex workers in the 1980s.

Courtesy of Multnomah County Sheriff’s Office

Jackson is schizophrenic. During the course of the interrogation, he denied knowing anything about the murders. But after hours of interviewing, Jackson told detectives he did remember the incidents and confessed.

Jackson’s trial is still pending and he remains incarcerated at the Multnomah County Jail.

The high court’s ruling Thursday stems from a pretrial motion.

In October 2017, Multnomah County Circuit Court Judge Michael Greenlick tossed out Jackson’s confessions.

Greenlick said in his oral ruling that the police were actively working to make things as bad as possible for Jackson.

“Which I think is very different than what you see in some circumstances where somebody is just told, ‘Hey, if you don’t admit, then this will happen.’ It’s like, ‘If you don’t admit, then you will be considered a monster; we will consider you a monster; and we will actively work to make this as bad as possible for you,’” Greenlick said in open court.

In its ruling, the Supreme Court pointed out something Greenlick said when he tossed out Jackson’s confessions.

“As the court put it if a defendant thinks he has no chance of prevailing in court, he ‘is much more susceptible to being under the influence of threats and inducements because it’s a little bit of ‘What harm will it do for me to confess?’”

While the ruling tosses out Jackson’s confessions, the case remains ongoing. Police told Jackson they found his DNA near two of the victims. It’s not clear how much prosecutors’ case relied on Jackson’s confessions.

The Portland Police Bureau referred questions to the Multnomah County District Attorney’s office.

“We are currently reviewing the opinion to assess any potential implications,” Brent Weisberg, a spokesman for the DA’s office wrote in an email. “This case is still pending prosecution and as such, we will not be able to comment any further.”

Weisberg referred questions regarding investigation techniques back to PPB, which declined to comment further.

In its ruling, the Oregon Supreme Court pointed out PPB detectives James Lawrence and Meredith Hopper appeared to have used what’s known as the Reid technique when they interrogated Jackson.

“That technique involves isolating a suspect in a small room to increase anxiety; confronting the suspect with accusations of guilt and emphasizing the strength of the evidence against the suspect,” the court wrote.

Jackson was in “poor physical health” at the time of the interrogation in addition to suffering from schizophrenia, depression, memory loss and “a history of blackouts.”

In its opinion, the court wrote: “given those characteristics, the detective’s interrogation methods — isolating him and cutting him off from his family … and encouraging him to see confession as a means of terminating the interrogation — resulted in admissions that were not reliable.”

The detectives told Jackson that no matter what he did he would be charged with murder, the court wrote. The justices pointed out that while the interrogation was hostile at times, the police officers largely appealed to Jackson to help the families of the victims by confessing.

“On the other hand, defendant is schizophrenic who experienced delusions in the past,” the court wrote, noting that he needs assistance shopping, can’t drive and has limited ability to walk. “His limitations are so significant that he receives disability services and [had] a live-in care provider.”

Marc Brown, the deputy public defender who argued for Jackson, said the court took a balanced approach.

“The court said the police, their job is to solve crimes, and sometimes in doing so they have to put pressure on the suspect,” Brown told OPB. “The court balanced that with the fact that we want to ensure that confessions are voluntary and ultimately reliable; that when someone says they did something that we can rely on that in court.”

Any appeal would be to the U.S. Supreme Court, though the state has not indicated if they will appeal the decision.