One of eight men convicted in the beating death of a Northeast Washington woman nearly 28 years ago told a D.C. Superior Court judge on Monday that D.C. homicide detectives beat him and forced him to lie about watching his friends attack and kill the wife and mother of six.

Clifton Yarborough, 43, wearing an orange jumpsuit, was the first witness called to the stand by the defense attorneys who say that prosecutors and detectives withheld evidence and coerced confessions from witnesses to obtain convictions in the Oct. 1, 1984, slaying of Catherine Fuller, 48.

Prosecutors said Fuller was walking to a store when she was pushed into an alley off Eighth Street NE, close to the busy H Street corridor, and beaten, sodomized with a metal pole and killed in a garage.

The defendants, ages 16 to 21 at the time, were convicted of first-degree murder and sentenced to between 35 years and life in prison. Also convicted were Kelvin Smith, Steven L. Webb, Levy Rouse, Timothy Catlett, Russell Overton and brothers Charles and Christopher Turner. Six of them remain incarcerated. Christopher Turner was released in 2010. Webb died in prison.

Defense attorneys for the men, along with the Mid-Atlantic Innocence Project, have asked Judge Frederick Weisberg to throw out the convictions and order the men released from prison, or grant a new trial.

Assistant U.S. Attorney James Sweeney said in court that Yarborough lied during the hearing on Monday and was telling the truth during the police interrogations. “These teens lied,” Sweeney said. “Each tried to minimize their own role in the attack and put everyone else in.”

During the 1985 trial, jurors watched a videotape of Yarborough’s account, in which he identified his friends as participants in the attack. In court Monday, Yarborough, who was 16 when he spoke to police without a parent or attorney present, said detectives beat him, stuffed his head into a toilet and threatened him, forcing him to say he saw his friends attack Fuller.

“I was scared. I was thrown around by detectives,” Yarborough said. He said he was at home when the attack occurred.

On Monday, Yarborough’s attorneys said their client is mentally impaired, with an IQ of 69.5, below the average 100. Rob Carey, one of Yarborough’s attorneys, said authorities targeted Yarborough because of his impairment, which Carey said “made him the most vulnerable” of the defendants.

In addition to the alleged coerced statements, Carey said there was an “avalanche” of evidence from witnesses who had told authorities that they had seen other people in the alley at the time of the attack — information that was not relayed to defense attorneys during the trial. One of those people was later convicted of killing a woman in the same area where Fuller was slain and in the same manner.

In the videotaped interview, Yarborough sat at a table, across from two detectives. He described the role each defendant played in the attack: covering Fuller’s mouth, holding her arms and sodomizing her with a pole. Yarborough told detectives that he was not part of the attack, but was in the alley when it happened.

On Monday, Yarborough said he recounted the scenario that had been laid out to him by one detective hours before the taped interview, when detectives beat him. He later testified that detectives told him he would not be arrested, but he was charged with first-degree murder.

Sweeney said that authorities investigated every lead and that all relevant information was given to the defense. He later acknowledged that “a perfect investigation doesn’t exist.”

The hearings are expected to take an additional two weeks.