Colorado's highest court ruled Tuesday that detectives violated a defendant's Fourth Amendment rights by interrogating a confession out of him while they executed a narrow court order to collect DNA samples.

The decision clarified a long-recognized rule that forbids police from questioning suspects who are detained under a judge's Rule 41.1 order, which allows police to collect "nontestimonial identification evidence" without probable cause.

The interrogation ban begins when a reasonable person in the suspect's position would not feel free to leave because "the rule authorizes a narrow intrusion into a suspect's privacy to collect evidence based, in part, on reasonable suspicion to believe that the suspect has committed a crime — the same standard used for an investigatory stop," Justice William Hood III wrote in the opinion.

The case stemmed from an investigation into an attempted sexual assault in 2020.

Police in Boulder, Colorado, obtained a Rule 41.1 order to collect DNA evidence from Angel Castro-Velasquez, a classmate of the victim. A detective called Castro-Velasquez and told him about the order, asking him to come to the station to allow them to collect a sample of his DNA using buccal swabs.

However, the order specified that the collection must take place during the daytime. A detective texted him to come the next day, but he did not respond, according to the opinion.

Detectives came to Castro-Velasquez's home the next morning and turned on audio recording just before knocking on his door. He let the officers into his home, and they began to ask him questions about the attempted sexual assault, according to court documents.

Castro-Velasquez confessed and gave details about the attack. They put handcuffs on him and took him to the station for the DNA test, the opinion said.

Castro-Velasquez sought to suppress his statements to police, contending they violated his Fourth Amendment rights, citing the state high court's 1988 opinion in People v. Harris, which forbids the interrogation of a suspect during the execution of a Rule 41.1 order. The trial court denied Castro-Velasquez's motion, and a jury ultimately convicted him.

An appellate panel overturned his conviction in 2024, saying Castro-Velasquez's confession and other statements should have been suppressed because he made them after he had been "seized" under the Fourth Amendment's definition.

Prosecutors sought the Colorado Supreme Court's review.

In Tuesday's opinion, Justice Hood wrote that encounters between police and citizens fall into one of three categories under Colorado law: consensual interviews, investigatory stops and arrests.

Investigatory stops require reasonable suspicion — a lower threshold than the probable cause that arrests require — but must also be brief and limited in scope, Justice Hood said.

Rule 41.1 "seizures occupy a similar spot along this continuum of permissible governmental intrusion on individual liberty," he wrote.

The state is represented by Philip Weiser, Gabriel Olivares and Caitlin Grant of the Colorado Attorney General's Office.

Castro-Velasquez is represented by Todd Narum of Peak Legal Services LLC.

The case is People v. Castro-Velasquez, case number 24SC533, in the Colorado Supreme Court.

--Editing by Covey Son.