BANGOR — A surprise witness rocked the courtroom Wednesday afternoon, telling the jury in Albert Cochran’s murder trial that he witnessed the gang rape and execution-style killing of Janet Baxter.

Irving “Skip” M. Kelley of Nebraska testified that at the time of the 1976 murder, he was acting as a drug “mule,” or carrier, for the FBI as part of a sting operation. The FBI was hoping to document drug activity between Perley Doyan of Waterville and a Waterville police officer, Cecil Cates, testified Kelley.

He said it was during a payoff for one of those drug transactions that he saw Baxter shot twice by Doyan — not Cochran.

The jury appeared so stunned by Kelley’s testimony that several jurors sat back abruptly in their chairs, while others suddenly leaned forward.

“I’ve got a picture in my mind that I’ll got to my grave with,” Kelley said to a hushed courtroom.

In earlier testimony, two state police troopers said they had been pressured not to pursue Doyan and his friends as suspects in the Baxter killing. One of the troopers claimed he retired because of the investigation, and the other said he was demoted in the midst of it.

The testimony heard by the jury of seven women and six men is intended to raise the issue of reasonable doubt.

Cochran, 61, is accused of abducting and killing Baxter, and DNA evidence is being used by the state to try to link him to her body, which was found stuffed in the trunk of a car in Norridgewock late at night on Nov. 23, 1976.

Throughout the trial, which today begins its eighth day, Cochran’s defense team, attorneys Michaela Murphy of Skowhegan and John Pelletier of Augusta, has launched an “alternative suspect” theory.

They are blaming a group of Waterville men — which included Doyan — for the killing and are producing witnesses who support that theory.

Kelley, appearing much older than his 58 years and casually dressed in black jeans and a plaid flannel shirt, said he has been hiding out since the killing, afraid for his life.

Doyan died three weeks ago on April 25 in Skowhegan, and Kelley agreed to testify the next day.

Under questioning by Murphy, Kelley said he knew the victim, Baxter, when he lived in Oakland, and that shortly before the killing, she had asked him for a loan, saying she owed Doyan $3,500.

While living in Pittsfield and working with the FBI, Kelley said he had returned from a drug run to Fort Lauderdale, Fla., on the morning Baxter died and had gone to a garage in Waterville to receive $20,000 in payment.

He waited around all day, Kelley testified, until late in the evening, when Doyan ordered two men, Armand Boudreau and Galen Lessard to “go do what you have to do,” and the two men left. Another man, Alan Pelletier, arrived with a satchel of money, said Kelley, and Kelley and Doyan went into a little office off the main garage floor to count the money.

“Then the bay door opened, and a light blue Chevelle with Armand Boudreau driving came in. Janet Baxter was in the passenger seat,” Kelley said. That car was followed by another car, a cream colored Ford.

Kelley said he looked out through a cubby hole in the office wall when he heard the men laughing.

“They were having sex with Janet Baxter in the back seat,” he said. “One would have sex, then step back, and another would go.” He testified that Boudreau went first, Pelletier second and that Lessard had unzipped his pants to go next.

“We were counting the money, and Doyan stopped and pulled up his shirt, and I saw a gun. He said, `I’ll put a stop to this s—,’ and he went out waving the gun,” Kelley said.

Doyan forced all the men to line up against the wall, some of them with their pants still down around their ankles, and he pulled Baxter out of the car by her feet.

“Part of her body was on the floor, and her head and arms were in the car, with her arms over her head,” Kelley recalled. “He fired two shots. It sounded like a small caliber. It sounded like snap, snap.”

Baxter’s daughter fled the courtroom in tears at the testimony.

At the prosecutor’s table, Assistant Attorney General William Stokes sat with his hands in front of his mouth, looking at Kelley. Defense attorney Murphy said later that her witness hadn’t been contacted by the prosecution about his testimony.

Kelley continued, “I looked down, and there she was with two bullet holes. She was bleeding pretty bad. She had nothing on below the waist but a pair of white socks.”

After shooting Baxter, Doyan turned to the men against the wall and said, “Let that show the rest of you bastards, that’s what you get when you mess with Perley Doyan,” Kelley testified.

“I figured I was next, and I grabbed the money and out the door I was gone,” he said.

Within days, Kelley had fled Maine, first to Virginia and then to North Carolina, and then eventually to Florida. He now lives in Nebraska.

Before he left, however, Kelley said he tried to tell his FBI contact that he had witnessed a homicide. “He told me that was a local affair and that he was only interested in the dirty cop,” Kelley said.

Under cross-examination, Stokes tried to discredit Kelley, raising the fact that Kelley had told a different story to an FBI agent in 1981. “You’re pretty good at making up stories,” Stokes challenged.

Kelley said the story was “made up to protect myself.”

The prosecutor then asked Kelley, with a disbelieving tone, “A woman was getting gang-raped and you were counting your money?”

Kelley maintained that he had nothing to gain by coming forward.

“I wouldn’t have told this story today if the defense team hadn’t found me,” he said. “I waited 22 and a half years for someone to listen.”

After the jury had been dismissed for the day, Stokes told presiding Justice Andrew Mead, during discussions on evidence admissibility, that “certainly the DNA evidence contradicts what Mr. Kelley has said.”

“The evidence clearly shows that [Cochran’s] sperm is inside Janet Baxter the night she is killed,” Stokes pointed out.

The defense, however, maintains that there were two sets of examination slides created with semen taken from Baxter’s body during the autopsy, and only one set was tested for DNA, therefore not ruling out the possibility of multiple semen donors.

Outside the courtroom, when asked about how Cochran’s semen got into Baxter, Murphy wouldn’t comment.

The defense is expected to wrap up its case this morning, and Stokes’ rebuttal should be complete by afternoon. The case should go to the jury by Thursday.