Sills has been in jail since he stabbed his neighbor, Benjamin Sánchez Nieto, 54, in the chest at the Town Creek Condominiums. A 13-hour standoff with law enforcement ensued with Sills as Sánchez Nieto ultimately was life-flighted to Eastern Idaho Regional Medical Center for treatment.

Prosecutor Erin Weisman said that Sills’ attack on Sánchez Nieto, just after midnight Dec. 31, 2020, was unprovoked. Sills lived in the apartment above Sánchez Nieto but the two men were essentially strangers.

“Over two years later, Sánchez Nieto wants to put this behind him,” Weisman said in court. “He’s happy to be alive and he thanks God every day, as he told me this morning.”

In a plea agreement signed Aug. 2, 2022, the original attempted murder charge was reduced, and Sills pleaded guilty to a felony charge of aggravated assault and battery. Ten years is the maximum imprisonment allowed.

Throughout the sentencing, Sills and his public defender, Elisabeth Trefonas, said he barely remembered the incident or ensuing law enforcement standoff. They argued that Sills was experiencing a psychotic break that lasted months after the stabbing.

The court deemed Sills was competent to proceed, which Trefonas did not contest.

“We did two evaluations to find if he was not guilty by mental episode, and both found he was in a psychotic episode,” Trefonas said in the sentencing. “The state hospital agreed he was in a psychotic episode.”

Weisman attributed Sills’ “strange state” at the time of the stabbing to “dabs,” a colloquial term for high-concentration THC, or tetrahydrocannabinol, oil. THC is the major psychoactive component in cannabis, and dabs can have a concentration of 80% more THC in comparison to traditional cannabis.

Weisman argued that Sills was in a “self-induced state” and reiterated that he was not found to be mentally deficient under the law.

Trefonas said the state hospital’s findings relying on dabs was “anecdotal,” and not substantiated with physical evidence.

“The state hospital gave the reason that it was because Sills was doing dabs, though his blood was never tested, dabs were never found, he had no failures on supervised probation and he graduated from Curran-Seeley,” Trefonas said in court.

Curran-Seeley is a nonprofit organization providing comprehensive alcohol and drug counseling and treatment in Jackson.

“Dabs can cause a psychotic break that typically last one to three days, but Sills was in this state for almost two months,” Trefonas said.

Sills, who appeared in person dressed in a navy blue suit, stated in a letter to Judge Owens that he has been a plumber in Jackson since 2003.

In the letter he said he remembers that a man attacked him in his bed that night and ripped off his crucifix necklace, and he defended himself, running after the man, at which point he saw law officers.

He theorized police believed he was on drugs because he may have been concussed.

Sills and Trefonas said he’s been clean of drugs since 2015 after growing up in a household full of drug selling, alcohol and violence.

Another issue Trefonas, Sills and Sills’ family raised during the sentencing was how long Sills had been in jail and the adverse effects that had on him, specifically long stints in solitary confinement.

“Sills spent 754 days in jail, 80% of that in solitary, and you don’t feel very human,” Trefonas said in court. “When you’re having a psychotic episode, being in solitary is a frightening experience. Our jail is meant to be a temporary holding facility; it’s not meant for over two years of detention.”

After apologizing directly to the victim, who sat in the jury box but declined to give a statement, Sills stated in court that he felt like a broken shell of a man.

“I feel like the dog that’s just being kicked, kicked, kicked, doesn’t even know what it’s done wrong,” Sills said. “I understand the severity of the crime … but there’s no sentence you can impose that is crueler than what’s already happened. I’m taking the plea because obviously I hurt someone. I had no intention to hurt anyone ever. I’m asking the court to give me a chance on parole. I want to try to make the money I need to make the restitution.”

Sills’ brother, Erick, and Erick’s wife, McKenna, appeared in court and spoke of Sills' character, saying he was not a violent man, and criticizing the judicial process.

“This court process has been the ultimate injustice,” Erick Sills said. “He was kept in isolation, not even evaluated in anything considered a reasonable timeline. Being in extended isolation has been hell. This is a man who helped raise many young men and women, including myself.”

Erick Sills was also critical of law enforcement in his statement, specifically of the 13-hour standoff.

“From the beginning of this debacle, it was kind of a charade for the police to do a 13-hour standoff,” he said. “Maybe it was a reason for the state to get out their toys. He had no weapons. I got there after midnight and I stated I could go up and talk to my brother, but police stated it was a safety issue. I don’t know what was happening there with the 13-hour standoff.”

Lt. Russ Ruschill of the Jackson Police Department said after the hearing that the standoff was “100% the responsibility of Riley Sills.”

He knew law enforcement was outside and he knew we wanted to speak to him,” Ruschill said. “He had every opportunity to give himself up peaceably. Since we knew he was alone in the apartment, we contained him. We opted for the safety of the public around him. We didn’t feel the need to do a dynamic entry into his apartment or use physical force on him.”

Past offenses also were brought up during Tuesday’s sentencing, and ultimately Owens imposed previously suspended prison time from past cases in which Sills had been given probation.

By Weisman’s count, seven of Sills’ past encounters with law enforcement were felonies.

“Mr. Sills has been on community supervision, probation before,” Weisman said in court. “He was on probation at the time of this offense, and … his criminal history is significant. Community supervision is not appropriate. His choices have continued to put others at risk for years. He’s been in treatment, he has run the gamut of time on probation.”

Between 2008 and 2019, Sills was charged with various offenses ranging from larceny for stealing and ingesting prescription pills from the medical room at the Teton County Jail, selling prescription drugs, stealing a $35,000 diamond engagement ring from a Teton Village residence and voyeurism for placing a hidden camera in the bathroom and bedroom of his apartment that he was sharing with two tenants.

Sills was on probation for the voyeurism charge at the time of the December 2020 stabbing.

On top of the eight to 10 years Owens handed down for the 2020 assault charge, she also ordered Sills to serve a range of prison time, between one and 10 years, for the past offenses to be served at the same time as his assault sentence, with credit for 1,693 days already served.

Sills also was ordered to pay $29,544.89 in restitution to Sánchez Nieto to cover his medical bills.

Owens said at the end of the two-hour hearing that she believed Sills did not remember the violent episode, but she did not feel Sills was a good candidate for probation.

“What makes you different than most defendants is I find a lot of them tell me what they think I want to hear to try to get a sentence, and I believe that you’re telling the truth, you’re sincere, I think you’re truly remorseful,” Owens said. “But I have to consider everything presented today, the serious and violent nature of the crime, the photograph we looked at today, and consider that the victim could have lost his life.”

During her sentencing argument, Weisman had shown photographs of Sánchez Nieto’s stab wound. It was four centimeters wide and seven centimeters long.

“I understand you were hoping for something different today, but I do want to remind you the state was generous in its offer to reduce what was an attempted murder to aggravated assault and battery,” Owens said in her sentencing. “I appreciate you taking responsibility as best you could under the situation … and I hope you can continue to address your mental health issues to set you up for success. You will likely be out within four years, be on parole and get to know that niece of yours and be a good citizen again in our community.”

This version of the article has been edited to clarify that Sills' relatives offered testimony about his character but did not specifically ask Owens to waive prison time. The spelling of Erick Sills' name has been corrected as well. — Ed.