PORTLAND — A 12-year-old boy was compelled to confess to a sexual-assault charge by two plainclothes police officers, the Oregon Court of Appeals has ruled in a decision that clarifies the circumstances under which such interviews with juvenile suspects take place.

PORTLAND — A 12-year-old boy was compelled to confess to a sexual-assault charge by two plainclothes police officers, the Oregon Court of Appeals has ruled in a decision that clarifies the circumstances under which such interviews with juvenile suspects take place.

The court found that the detectives created a "police-dominated atmosphere" when the sixth-grader's principal at an alternative school brought him to an interview room with just the two officers, who began to question him and escalated the nature of the questions as the interview took place for more than 90 minutes.

The boy's attorneys asked that the confession in the interview should be suppressed. A Multnomah County juvenile court judge denied that request, but the ruling issued Wednesday sided with the boy's attorneys. The case was sent back to juvenile court.

The boy suffered from behavioral issues, which led him to be enrolled in the alternative school. His parents weren't notified of the interview.

"At a minimum," appeals court judge James Egan wrote in the opinion issued Wednesday, "the detectives should have known from the circumstances that youth was in a category of children that require a heightened level of precautions to ensure that he understood that he was not required to stay or answer the detectives' questions."

The boy admitted to conduct that would have constituted second-degree rape if it were committed by an adult. The original charges included sexual acts with a 10-year-old girl for which prosecutors originally sought charges of rape- and sodomy-equivalents in the juvenile system.

At one point, a detective opened a DNA testing kit, put on blue gloves and asked the boy if he would consent to an oral swab to collect DNA evidence. The boy did not respond.

At the heart of the case is the question of whether the circumstances of the interview compelled a confession. Prosecutors for the state argue it did not.

They say the detectives didn't dress in uniform to avoid seeming imposing, and kept the questions low-key. They kept their voices down, prosecutors argued, and avoided leading questions, using simple language. When the interview began, the detectives told the boy he was free to leave, and he didn't have to answer any questions.

Finally, the detectives told the boy he would not be arrested that day, no matter what happened during the interview, and the boy was cognizant enough to decline the officers' request to record the interview.

The act of officers interviewing juvenile suspects in school does not always constitute "compelling circumstances." A 1993 case ended with the decision that an officer who conducted a 20-minute interview with a 13-year-old boy did not create an atmosphere that coerced a confession.

In that case, the officer had told the boy that he was not under arrest, that he did not have to talk to the police officer and that the boy knew that he could leave if he wanted. The court previously found that "an interview that would not be 'compelling' for an adult might nonetheless frighten a child into believing that he or she was required to answer an officer's questions."

But the court found that the case decided Wednesday did indeed qualify as compelling and coercive.

"Throughout the entire interview, the detectives repeatedly renewed their directive that youth had to tell his parents 'the truth,' despite youth's statements that he feared doing so and that he had not done anything wrong," Egan wrote.

"We conclude that a reasonable 12-year-old of similar age, knowledge and experience, placed in youth's situation, would have felt required to stay and answer all of the detective's questions."