The Colorado Court of Appeals has issued two significant decisions arising out of the criminal prosecutions of Aurora Fire Rescue paramedics Jeremy Cooper and Lieutenant Peter Cichuniec for their roles in the treatment of Elijah McClain in August 2019.

In separate opinions issued June 4, 2026, the court reversed Cooper’s and Lt. Cichuniec’s conviction for criminally negligent homicide. The court ordered new trials on those charges. The court, however, upheld Lt. Cichuniec’s conviction for second-degree assault based upon the jury’s finding that the administration of ketamine was unlawful under the circumstances.

The cases stem from an encounter between Aurora police officers and 23-year-old Elijah McClain. According to the court, McClain and was walking home from a convenience store when a 911 caller reported a “sketchy” looking black male wearing a ski mask, “walking quickly” and “moving his arms.” Aurora police were dispatched.

Quoting from the decision:

• Aurora police officers saw Mr. McClain. Police body-worn cameras recorded the interaction.
• When the officers asked Mr. McClain to stop, he said he had a right to walk where he was going and continued walking.
• Three officers then tried to physically restrain Mr. McClain.
• One repeatedly told him to “stop tensing up,” and one told him to “relax or I’m going to have to change this situation.”
• Mr. McClain objected to being stopped, and the officers began to struggle with him.
• As the officers continued to struggle with Mr. McClain, one of them said, “He just grabbed your gun,” to one of the other officers.
• The officers pushed Mr. McClain to the ground.
• An officer tried to put Mr. McClain in a carotid control hold, whereby a person applies pressure on someone’s neck with his bicep and forearm.
• When that effort failed, another officer put Mr. McClain in a carotid control hold.
• The second hold cut off blood flow to Mr. McClain’s brain, causing him to temporarily lose consciousness.
• When Mr. McClain regained consciousness, he told the officers that he couldn’t breathe. He later vomited.
• An officer asked a dispatcher to send paramedics to treat Mr. McClain because he had temporarily lost consciousness.
• Cooper; his supervisor, Lieutenant Peter Cichuniec; and two nonmedical fire department personnel (an “engineer” and a firefighter) arrived a few minutes later.
• They saw two officers restraining Mr. McClain on the ground.
• The police officers told Cooper and Cichuniec that Mr. McClain had “passed out,” was “definitely on something,” and was “acting crazy.”
• One of the officers said that the officers had tried to “put a carotid on the guy” and had done so, which “put [Mr. McClain] out.”
• Officers also said Mr. McClain had shown “incredible” and “crazy” strength from “whatever he’s on” and “almost did a pushup with all three of us on his back.”
• Based on the information the officers had told them and their visual assessment of Mr. McClain, Cooper and Cichuniec concluded that Mr. McClain showed symptoms of a condition called “excited delirium.”
• They agreed they would inject Mr. McClain with ketamine.
• Cooper told the officers that the paramedics would inject Mr. McClain with ketamine once the ambulance arrived with the drug. (An ambulance with two emergency medical technicians (EMTs) had also been dispatched to the scene.)
• Once the ambulance arrived, Cooper and Cichuniec determined that 500 mg of ketamine was the correct dosage to give to Mr. McClain based on his weight (which Cooper estimated at about 220 pounds (100 kg) and Cichuniec estimated at 187 pounds (85 kg)) and his degree of agitation. (In fact, Mr. McClain weighed only 143 pounds.)
• Either Cooper or Cichuniec told an EMT to prepare it.
• Once the EMT did so, Cooper injected it into Mr. McClain.
• Sometime after Mr. McClain was placed in the ambulance, Cichuniec noticed that he had stopped breathing.
• He told an EMT to check Mr. McClain’s pulse. When the EMT couldn’t find one, the EMTs began CPR.
• Mr. McClain was subsequently admitted to a hospital. Doctors declared him brain dead a few days later.

The Adams County Coroner classified both the cause and manner of death as “undetermined.” The local district attorney declined to prosecute any of the involved officers or paramedics.

Governor Jared Polis subsequently issued executive orders directing the Colorado Attorney General to investigate and, if warranted, prosecute those responsible for McClain’s death. A state grand jury later indicted Cooper, Lt. Cichuniec, and three Aurora police officers.

At trial, prosecutors argued that the paramedics acted contrary to their medical training and applicable protocols when diagnosing excited delirium, determining McClain’s weight, selecting the ketamine dosage, administering the drug, and monitoring his condition afterward. The jury convicted Cooper of criminally negligent homicide and acquitted him on all other charges. The same jury convicted Lt. Cichuniec of criminally negligent homicide and one count of second-degree assault involving the unlawful administration of a drug, while acquitting him of the remaining charges.

On appeal, both defendants challenged the Attorney General’s authority to prosecute after the elected district attorney had declined to bring charges. They claimed that Colorado law required the appointment of a special prosecutor. The Court of Appeals rejected that argument, holding that Colorado’s special prosecutor statute is not the exclusive means of pursuing a prosecution that a district attorney declined to pursue. According to the court, a separate statute authorizes the Attorney General to prosecute criminal matters when directed to do so by the Governor, and the Governor’s executive orders in the McClain matter were lawful.

The central issue in both appeals concerned the jury instructions defining criminal negligence, the mental state element necessary for the crime of criminally negligent homicide.

The prosecution’s theory throughout trial was that Cooper and Lieutenant Cichuniec violated the standards applicable to trained emergency medical professionals. The defense requested an instruction informing the jurors that criminal negligence should be measured against the conduct of a reasonable paramedic in the same circumstances. The trial court instead instructed the jury using the statutory definition of criminal negligence, referring only to the conduct of a “reasonable person.” When jurors later asked for a definition or description of the applicable standard of care, the court directed them back to the instructions already provided, namely – the “reasonable person” standard.

The Court of Appeals concluded that approach was erroneous. The court held that, in a case involving medical treatment provided by trained paramedics, the relevant standard is not that of an ordinary layperson. Rather, criminal negligence must be evaluated based upon the conduct of a reasonable person possessing the actor’s knowledge and experience and operating under the circumstances known to the actor. For Cooper and Lt. Cichuniec, that meant the standard applicable to a reasonable paramedic treating a patient in McClain’s condition. Because the jury was not properly instructed on that standard, and that such an error was not harmless, the court ordered new trials for both defendants on the criminally negligent homicide charges.

Lt. Cichuniec raised additional arguments concerning his second-degree assault conviction. The prosecution’s theory on that charge was that ketamine had been administered to McClain without a lawful medical purpose. The Court of Appeals rejected Lt. Cichuniec’s challenges to the sufficiency of the evidence, the jury instructions, and the admission of expert testimony. The court concluded that sufficient evidence existed for the jury to find that the ketamine administration lacked a lawful medical purpose and affirmed the conviction.

The court also addressed an issue unique to Lt. Cichuniec’s role as an alleged complicitor. The prosecution charged both men as principals and as complicitiors. At trial, however, the evidence that that Cooper administered the drug. As a result, Lt. Cichuniec could not realistically be guilty as the principal actor on the unlawful-administration-of-drugs charge. His liability depended on the theory that he intentionally aided, encouraged, or participated in Cooper’s commission of the offense.

Lt. Cichuniec argued that because the jury acquitted Cooper of the same second-degree assault charge, his own conviction as a complicitor could not stand. In essence, he contended that if the alleged principal was found not guilty, the complicitor should also be found not guilty.  

The Court of Appeals rejected that argument. The court explained that Colorado’s complicity statute requires the prosecution to prove that another person committed the elements of the underlying offense. It does not require that the principal actually be convicted of the offense. Nor does an acquittal of the principal automatically bar conviction of a complicitor.

Note that most jurisdictions use the term accomplice or accessory before the fact rather than complicitor.

As a result of the decisions, the criminally negligent homicide convictions of both paramedics were reversed and remanded for new trials. Lt. Cichuniec’s conviction for second-degree assault was affirmed.