The Colorado Supreme Court on Monday blocked a defendant accused of a cold case murder from introducing testimony about how his autism spectrum disorder may have contributed to behavior police perceived as deceptive.

The court’s unsigned Sept. 8 order stated, without elaboration, that the intended expert testimony did not meet the requirements of state law. Prior to the decision, the defense, prosecution and trial judge claimed the other side misunderstood the implications of the underlying evidentiary ruling.

Prosecutors originally charged John Michael Angerer in 2010 with the murder of Angela Wilds in South St. Vrain Canyon several years before. However, there was not probable cause to bring him to trial.

After further investigation, a grand jury again indicted Angerer for Wilds’ murder in 2023. The defense hired an expert to psychologically examine Angerer and she diagnosed him with autism spectrum disorder. Shortly before trial, the defense listed the expert as a witness who could testify about autism.

The prosecution objected, arguing the “mental condition” evidence did not go through the process outlined in Colorado law. 

“So, as I understand the mental health issue,” said District Court Judge Andrew Hartman at a June 2 hearing, the expert will describe “that the defendant’s diagnosis perhaps makes him suggestible or somewhat receptive to certain types of interrogation or questioning that may have occurred in this case?”

Correct, replied defense lawyer Johanna Boyd. She elaborated that law enforcement witnesses might testify at trial that Angerer avoided eye contact and repeatedly looked down, which were “indicators of somebody who struggles with social cues” rather than deception.

Prosecutor Carlos Rueda argued that Colorado law requires defendants to go through certain steps before introducing expert evidence of a defendant’s mental health condition, including a court-ordered examination.

“But if one of the detectives comes and says, ‘I show him the photograph of the grave, and he got uncomfortable’ in the middle of trial, now I have to defend with some expert?” Rueda asked.

Hartman found the attempt to introduce the autism expert’s testimony was “not fully compliant” with the law, but also “not fully noncompliant.” He decided if the detectives wound up testifying about Angerer’s mannerisms, then “it’s possible” the defense could use its expert to counter what they say. The ruling would have to be made “in context.”

“I just want a crystal-clear ruling because there was never a court-ordered examination,” Rueda responded.

“You just have to kind of take the win here,” Hartman said, adding it was “unlikely” the autism expert would testify.

The district attorney’s office quickly filed a motion to reconsider. After Hartman did not immediately act, the prosecution asked the Supreme Court to step in.

The autism diagnosis “is expert opinion evidence concerning Defendant’s mental condition, and admissible only if Defendant had complied with (the law) — which he indisputably has not. It is therefore error for the district court to consider allowing such evidence,” wrote Senior Deputy District Attorney Ryan Day.

Unusually, Hartman quickly issued an order accusing the prosecution of failing to “accurately recite the court’s ruling.” He also published a second written order asserting he was, in fact, excluding Angerer’s autism diagnosis from trial.

“However, should considerable testimony at trial by law enforcement regarding Defendant’s eye contact, lowered tone, or other behaviors during the interviews arise and be used to establish Defendant’s dishonesty,” Hartman elaborated, “the Court may reconsider whether this implicates Defendant’s rights to a fair trial such that limited expert testimony by (the expert witness) to rebut such inferences may be appropriate.”

Angerer and Hartman responded to the prosecution’s petition to defend the evidentiary ruling. The defense argued Hartman’s decision gave the prosecution what it wanted by excluding the mental health evidence, and the “mischaracterization” created “a fictional issue for this Court’s review.”

The district attorney’s office replied that Hartman explicitly left open the possibility of allowing the expert to testify.

If that were to happen, the prosecution has “no meaningful ability to investigate or challenge Defendant’s underlying diagnosis. Because Defendant did not notice his mental condition evidence, the (prosecution does) not have an autism expert of their own,” wrote Day. “These are the precise reasons that proponents of mental condition evidence must comply with the statutory requirements.”

In its order, the Supreme Court told Hartman to strike the portion of his decision allowing for the possibility of the autism expert’s testimony at trial.

“We now conclude that the defendant may not present the proposed expert mental condition testimony because he did not comply with the requirements” of the law, the court wrote.

The case is People v. Angerer.