DAWN HAD JUST BROKEN OVER CAYUGA Lake in upstate New York on June 9, 1991, when gunfire cut through the Sunday morning silence. There were four shots in quick succession. Then, say police, two teenagers—a boy and a girl—rushed from a tiny summer cottage and jumped into the back of a pickup truck, barely hanging on as it sped away.

The gunfire awakened neighbors, who assumed someone was shooting at water snakes. But that afternoon Donald Graham, a food sciences professor at nearby Cornell University, realized he had not seen his next-door neighbor, Bruce Kellogg, all day. Graham led an impromptu search party of neighbors to the Kellogg cottage, where they found Kellogg's body on the sleeping porch. He had been shot in the head four times.

New York State police thought it unlikely that the killer or killers came from the Cayuga Lake area, where Kellogg, 43, had grown up. "There was no motive," says Capt. Allen Emerson. "He didn't get into weekend fights. He was well liked." Instead, Emerson sent several investigators to Harrisburg, Pa., where Kellogg, a supervisor at an air-conditioning repair company, had been living for 18 years. Almost immediately they focused on Kellogg's 26-year-old wife, Laurie—and four of the many teenagers who hung out at the Kellogg house. All four said that on the night before the killing they had been roller-skating with Laurie—a substitute schoolteacher and mother of two small children. But, Emerson says, "their alibis were shaky, and one by one their stories crumbled. The truth expressed itself very quickly."

The truth, he says, involves a copy cat murder patterned on the celebrated case of Pamela Smart, a New Hampshire schoolteacher who was convicted in March 1991 of persuading three teenage boys to murder her husband. In fact, no one disputes that Laurie and the four teenagers were present at the Kellogg lake cottage at the time of the shooting. All five admitted driving 200 miles through the night from Harrisburg to Cayuga Lake and driving back after Bruce was killed. All five gave statements to police saying that two of the teens—Denver McDowell, now 19, and Nicole Pappas, now 17—entered the cabin, and that McDowell fired the fatal shots.

But as Laurie Kellogg's murder trial opens in Waterloo, N.Y., this week, there is one major area of disagreement: What was her role in the killing? Her attorney, Peter Orville, says she had none and that shooting Bruce was entirely the teenagers' idea. But two of the four teens—McDowell and Kristi Mullins, now 16—tell another story. McDowell has pleaded guilty to both murder and conspiracy to murder and Mullins to being an accessory. Each will testify at Laurie's trial and at the murder trial of the two remaining teens later this summer. The motive for the crime? The teenagers say Laurie claimed Bruce was abusing her—physically, verbally and sexually.

Laurie first moved in with Bruce in 1981 when she was a 16-year-old high school student. Bruce, then 33, had recently separated from his first wife, Debra, and was sharing custody of their two children, Kevin, then 6, and Kellie, then 2. In late 1987, after Laurie became pregnant, Bruce finalized his divorce from Debra and married Laurie. Their first son, Kyle, was born the following February and their second, Kristopher, a year later. In 1988 Laurie earned a degree in elementary education from the Harrisburg branch of Penn Stale University.

Laurie's friends and family say her life with Bruce was an ordeal of domestic servitude. She had to cook, clean, work part-time jobs (waitressing, delivering pizzas, sorting for UPS, substitute teaching), take care of her two infants and help raise his two older children—all on a meager budget. "She was really tired all the time," says her stepfather, Ed Francis, 59, a vacuum cleaner salesman. "We worried about her health because she looked so bad."

Laurie's associates also say Bruce abused her. Every morning, her attorney says, Bruce would give her a list of things to do. Every evening he would go over the list. If she failed to do everything, Orville says, Bruce would force her into painful sexual acts later that night. Once, Kellogg inserted a loaded pistol in her vagina, Orville says. Another time, he put a loaded shotgun in her mouth. The lawyer claims Kellogg once hit her so hard he punctured an eardrum and says he repeatedly threatened to kill her if she ever tried to leave him. (Her friends say that on two occasions she did try to leave but that he talked her out of it.)

Even so, Laurie never reported any abuse to authorities, and Bruce's family and friends maintain that it never occurred. "I never saw him hit her. I never even saw him grab her," says his son Kevin, now 18, who lived with the couple six months a year. By all accounts though. Bruce did have a problem with his temper. "He was scary when he got angry," Kevin admits. "He would slap me. But that was pretty much the extent of it."

Apart from the disparity in their ages, the couple had major lifestyle differences. Bruce was an avid hunter, fisherman, archer and golfer. But when he was away on his many hunting or fishing trips, Kevin says, Laurie led her own life. Once, he recalls, he discovered three "hippies" playing the guitar in the living room at 5 A.M. And Jim Gittings, 27, a Harrisburg warehouse supervisor, says he had a brief affair with Laurie during the summer of 1990. But even as he was trying to break it off, he says, Laurie would call frequently and complain about her husband. " 'Bruce is so bad,' " Gittings quotes her as saying. " 'He hits me. He beats me.' But I never saw a mark on her, and I saw her nude."

To Bruce's displeasure, Laurie was also a magnet for area teens. "Laurie was the neighborhood den mother," says her own mother, Linda Francis, 46. "She was the neighborhood babysitter." Some of those she sat for grew up to sit for her children, Francis says. One of those was Nicole Pappas, a cosmetology student who once lived across the street before her parents split up. Laurie acted as her surrogate mother, friends say, something she also did for unwed mother Kristi Mullins. Kristi and her baby, Chasidy (named after Cher's daughter, Chastity, but deliberately misspelled), lived with the Kelloggs off and on after her mother threw her out of the house. As a result one of Kristi's boyfriends, Charles Sebelist, now 17, a lanky heavy-metal fan with a flair for art, also hung out at the Kellogg house. Another youth, Denver McDowell, who has an extensive juvenile record, lived across the street but moved into a tiny camper on the Kellogg front lawn after a fight with his father. He told authorities he was in love with Laurie, but both insisted they did not sleep together.

Sometime in April 1991, McDowell repeatedly asked two friends, Robert "Boober" Myers, 19, and Thomas Noggle, 17, to kill Kellogg. "He said he'd give us a brand new Ford Bronco and $1,000," Myers recalls. They turned him down. "We just didn't want anything to do with it," Myers says. "We just thought he was carrying on." At about the same time, Laurie allegedly made a similar offer to a family friend, a Harrisburg truck driver. "I just let it go in one ear and out the other," he says. "I was sure she was just joking around."

That is exactly what she was doing, insists her lawyer, who maintains his client had nothing to do with McDowell's approaches to Myers and Noggle. Orville says the teenagers were upset by Laurie's stories of abuse and often played a game, which he calls 101 Ways to Kill Bruce. "But I don't think anyone, except Denver, ever was serious," he says.

On Saturday, June 8, Bruce left Harrisburg around 5 A.M. for Cayuga Lake to ready his 18-foot speedboat for the bass season, which opened the following weekend. That night, Orville says, Nicole Pappas and another neighborhood girl confided to Laurie that Bruce had sexually abused each of them when they were 8 or 9 years old. Laurie decided to drive to Cayuga Lake to confront him, Orville says, and took McDowell, Pappas, Sebelist and Mullins with her, both for protection and as witnesses. The gun, he says, was brought by McDowell without Laurie's knowledge. When Laurie discovered he had it, Orville says, she told him to "put it away."

There are two versions of what happened at Cayuga Lake. Orville says that at the last minute Laurie got cold feet. But before she could drive away, he says, McDowell and Pappas slipped into the cottage on their own. Not so, McDowell said in an interview before lawyers stopped him from speaking to the press. He told the Syracuse Herald-American shortly after his arrest that Laurie talked him into killing Bruce. " 'Just think how my boys will be, and how I will be, and how the [abused] girls won't have to live with what happened to them anymore,' " he quoted her as saying. " 'It would all be over with.' "

A Waterloo, N.A., jury must now decide who is telling the truth. If it decides Laurie Kellogg is another Pamela Smart, she faces the same fate, a lifetime in prison while her two children are raised by her parents. "She's a good mother," says Polly Murphy, owner of a children's bookshop near the Kellogg home. "I never thought she'd do anything to separate her from her kids." But another friend disagrees. "Laurie," she says, "always found ways to screw herself."