A St. Paul man on trial in the gang rape of a teenage girl told police he interrupted the attack, a police officer testified Monday.

In a December 2011 interview with police, Mang Yang said he knew other men and boys at a house party planned to rape the girl, then 15, but that he was outside when it apparently began, testified Officer Jimmy Yang, a gang investigator on the case. Mang Yang, 24, told police he was outside to retrieve the girl's female friend, who had left to determine the house's location so a friend could pick them up.

Mang Yang said he tried to get back into the foreclosed house on White Bear Avenue, but the door was locked, testified the officer. He knocked, and one of the other eight co-defendants in the case let him in. He told police he heard screaming coming from one of the bedrooms, so he opened the bedroom door, causing the other defendants to flee, Officer Yang testified.

Mang Yang's account of the night contradicts testimony from co-defendants Shaileng Lor and Xou Yang, who testified last week that he planned the attack and failed to help the victim when she ran to him for assistance. Xou Yang also said Mang Yang told one person to cover the girl's mouth, and that he called for a turn raping her.

Yang's attorney, Christopher Champagne, tried to poke holes in their stories by noting that Lor and Xou Yang, both 17, received plea deals with significantly lower prison terms in exchange for their testimony. Both are serving eight years in prison. Champagne also noted that they are close friends, and that they had an opportunity to "get [their] story straight," laying the blame on his client.

Although Lor and Xou Yang both said Mang Yang was in the house when the men and boys converged on the girl and dragged her kicking and screaming into the bedroom, their memories of where he was in that room during the attack were murky. They placed Mang Yang at the back of the bedroom by the door, away from the activity as others held onto the girl's arms and legs as Vang Vue raped her. Champagne focused on that weakness, asking Lor if he believed Mang Yang was in the bedroom only because he believed Mang Yang had been behind the group as they dragged the girl into the room.

Testimony and audio played in court Monday of interviews Mang Yang gave to police in December 2011 and March 2012 further clouded that issue, which has become a focal point of Champagne's questioning. In the second recording, Officer Yang asked Mang Yang if he was in the room. Mang Yang said he was.

"And he says, 'Can I explain?'" Champagne asked Officer Yang in cross-examination.

"Yes," said the officer, adding that the interview never went down that road.

"One explanation for why he was in the room was he knocked on the door and alerted everyone that someone had called the cops?" Champagne asked.

"Yes," the officer said.

Lor testified that Mang Yang mentioned the cops, and everyone fled. The victim's friend testified last week that she was a few houses down looking for street signs when Mang Yang pulled up in his car to retrieve her. She testified that that's when she saw the others run out the front door.

In an attempt to show that other defendants in the case possibly had intentions of raping the victim, Champagne focused on a party that occurred a week before the attack. Others in the case -- not Mang Yang -- were in a bedroom with the victim, Champagne said. The victim's friend, now 19, testified that she was at that party, and had forced her way into the bedroom because she feared the girl would be harmed.

The friend also testified that at the White Bear Avenue party, Mang Yang ignored requests to drive the girls home, and that he and the other co-defendants plied the victim with several beers and shots of brandy.

Mang Yang and eight other men and boys were charged in the Nov. 17, 2011, attack. Five have pleaded guilty. Yang's trial is expected to wrap up this week. Two other defendants are scheduled to go to trial this month, and a juvenile case remains active.

Chao Xiong • 612-270-4708 Twitter: @ChaoStrib