JUST BEFORE NOON LAST MAY 17, A BLACK Toyota pickup rolled to a stop on Shelter Road in Lewiston, Idaho. Out stepped a middle-aged white man carrying a rectangular box. He strolled into Tony's Specialized Automotive, a car repair shop.

"Is Ron Bingham here?" the man asked. Robert Warnock, a mechanic, pointed out Bingham, who was working under a raised pickup. Bingham's wife, Luella, was standing nearby.

"I got something for you," Warnock heard the man tell Bingham. "I got something real special for you."

With that, police say, the man pulled a Tec-9 mini-assault weapon from the box and pumped 23 rounds into Ron Bingham's chest, arms and hands.

"You bastard!" Luella Bingham screamed. As she started to flee, he cut her down too, killing her with six shots in the back.

The cold-blooded murders stunned this scenic Snake River Valley community of 31,000. The Binghams were longtime residents and the parents of a 16-year-old son. Equally shocking, however, is the identity of the man accused of the double slaying, Ken Arrasmith, 44, a former Asotin County deputy sheriff.

Although the killings are viewed as a tragedy, it's the alleged murderer whom many townsfolk consider the real victim. "Ken Arrasmith is a family man who couldn't stand to see his daughter violated," says Diane Paine, a bartender at Campbell's Corner, a popular gathering spot. "It sounds callous, but I say good riddance to the Binghams."

The Binghams, says Arrasmith, 44, forced drugs on his then-15-year-old daughter Cynthia and sexually assaulted her on several occasions. He also says the county's 10-member sheriff's department knew of at least one of these accusations a month before the shootings but failed to arrest the Binghams. For years, Arrasmith contends, the Binghams "preyed on teenagers who were not getting along with their families," and the police "were either indifferent or too incompetent to stop them." Frustrated and fearing for his daughter's safety, his attorney says, he acted in self-defense.

Authorities will say little about the case other than that they were investigating the rapes at the time of the shootings. Given the Binghams' history, there was good reason for police to have taken Arrasmith's charges seriously. In 1978 the couple were accused of abusing their two nieces, then ages 13 and 11, though prosecutors dropped the case after the girls' father moved them out of state and refused to allow them to testify. Then, in 1984, Ron Bingham pleaded guilty to raping his son's 16-year-old babysitter but served only 18 months in prison.

"We wouldn't take a wild grizzly and turn it loose on our children, but that's what the courts are doing by releasing these predators," says Arrasmith, speaking from behind bars at the Nez Perce County jail, where he is awaiting trial next month on first-degree murder charges, which can carry the death penalty. Arrasmith has pleaded not guilty; his attorneys will argue that the shootings were justifiable homicide. "What would you do if it was your daughter?" Arrasmith asks.

Arrasmith's question has struck a nerve. Since the murders, 15 women have come forward to say the Binghams abused them when they were between 12 and 16. Arrasmith has received hundreds of letters of support from across the country and $30,000 in donations for a defense fund.

"Asotin County should have done something about Ron Bingham years ago," says Tammy Evans, 32, one of the 15 women who came forward. A supermarket employee, Evans filed rape charges against Bingham in 1980, when she was 17, but says she dropped them when prosecutors were slow to act: "They did absolutely nothing."

As for the Arrasmith and Bingham families, they were hardly unknown to each other. Arrasmith's parents live just a half mile from the Binghams on a peaceful road in Clarkston, Wash., across the river from Lewiston. In fact, Arrasmith and Luella Bingham rode a school bus together as teens.

Ken, the only boy among the six children of Charles and Evelyn Arrasmith, had long seemed a solid citizen to most people who knew him in Lewiston. After graduating from Clarkston High School in 1969, he drove a truck, did road maintenance work and joined the Asotin County sheriff's department in 1975. He left in 1978 after he backed the losing candidate in the election for county sheriff. A long-haul trucker at the time of the shootings, he was often the first person his parents and sisters turned to for help. Yet Arrasmith has seen his own share of trouble. He is twice divorced, and his first wife, Linda Bartlett—Cynthia's mother—filed a complaint against him in 1989 for nonpayment of child support. In 1987 he pleaded guilty to a drunk driving charge and lost his license temporarily. He had no other police record until the shootings.

Ron Bingham, who was 47 when he died, did odd jobs as a carpenter, raised rabbits for sale, repaired cars and often took in troubled teenagers at the small brown-and-white, ranch-style house he shared with his wife, son and mother-in-law. Raised by an aunt and uncle in Iowa, he learned when he was 12 that his mother was actually the woman he had been told was his aunt. His father had sired, by many accounts, 26 other children. "Ron was very bitter when he found out the truth," says his mother-in-law, Rilla Smith. He left home at 14 to work in a coal mine, enlisted in the Army at 17 and earned three combat medals in Vietnam, including a Bronze Star.

On a holiday in the Pacific Northwest in 1969, he met Luella, then 16. A few months later she dropped out of high school to marry him. "He was the only boyfriend Lu ever had," her mother says. Later, however, their relationship became less exclusive. "They were definitely what you would call swingers," says Smith, a 69-year-old grandmother with silver-rimmed bifocals. The Binghams often engaged in sex with other couples at a nearby motel, says Smith. "This was not the world I was raised in, people swapping wives and what have you," she says. But Smith insists the Binghams kept these activities out of the home and away from their son Joshua, now an honor student at Clarkston High School. "I stayed out of it," says Josh, who was aware of his parents' secret life. "They kept it from me."

Indeed, to many in town the Binghams seemed an unexceptional couple. Ron and Luella volunteered at their son's Head Start program; Luella clerked at JCPenney. Whatever their sexual proclivities, they were certainly not rapists, Smith says. Yet in 1978, Smith's own granddaughter Lora May Smith, then 13, told investigators her Aunt Luella had forced her to have oral sex with her. Lora May's sister Janell, then 11, said the Binghams had made her watch them have sex and photographed her naked. Janell told her parents and repeated her story to a social worker, but the case never went to trial because Luella's brother—the girls' father—moved his family and refused to allow the girls to testify against his sister.

Then, in 1984, Tina Cole Turner, who babysat Josh, told authorities that Ron and Luella came home one night and attacked her as she slept on their living-room couch. Ron maintained the sex was consensual. But he agreed to plead guilty when prosecutors offered to drop charges against Luella.

The Binghams eventually blended back into the community. (In fact, many in Lewiston had written letters to the court vouching for Ron's character before his sentencing in the Turner case.) Then, last March, Cynthia Arrasmith moved in with the Binghams. She had been living in a trailer with her boyfriend on the Binghams' property, and when they split up, she stayed. The teenager had had a difficult time since her parents' 1979 divorce. She had used drugs and had often run away from her mother's house. "I guess she kind of felt abandoned," says Ken Arrasmith, who had moved to Sunnyside, Wash., 180 miles away. He wanted Cynthia to live with him, but she preferred to stay in Clarkston, where she had grown up. Arrasmith didn't favor Cynthia's living with the Binghams, he says, "but I figured it was better than not knowing where she was." He claims he didn't remember earlier charges brought against the Binghams.

Late one night in March, Cynthia says, the Binghams attacked her for the first time. "It was about 1 in the morning. I was trying on some of Luella's clothes in her bedroom. She had really neat clothes," Cynthia recalls. "All of a sudden, she pushed me on the bed and started doing stuff. When she got done, Ron came in."

Ron Bingham, Cynthia alleges, often forced her to take drugs. She says he would stand over her "yelling, screaming and cussing" until she swallowed the pills—sometimes Valium, sometimes methamphetamine. (Traces of methamphetamine were found in Ron and Luella Binghams' blood, according to their autopsies.) Though frightened, Cynthia didn't flee. "Ron always said, 'If you ever leave, we'll find you,' " she says. He emphasized the point, she adds, by flashing a gun.

Last April 18, Cynthia believed she might finally be rescued. Acting on a tip from an informant that the Binghams were selling drugs, police searched their home. According to the officers' report, they found an ounce of marijuana and an eighth of an ounce of methamphetamine on two teenage boys at the house. The officers took the boys into custody, but the Binghams weren't charged.

One of the policemen asked Cynthia for her mother's name and phone number. "They're like, 'Shouldn't we call her mother?' And Ron jumps in and says, 'No, she's got permission to be here. She lives here,' " Cynthia says.

Why the police let the matter drop remains a mystery to the Arrasmith family. "They didn't bother to call her mother. They didn't bother to call her father or Child Protective Services. What in the sam-hell are we paying these people for?" complains Dave Hoidahl, a close family friend. (So far, there are no answers. The head of the task force that conducted the search, the county sheriff and the prosecutor in the Arrasmith case declined to comment on the officers' actions.)

On May 6, Cynthia was still living with the Binghams. That day, while visiting her mother, Linda, and older sister Jennifer, she blurted out her story of sexual abuse. She begged them, "Don't call the cops. If you do, they'll kill me."

Instead, they called Ken Arrasmith. By then, a friend had taken Cynthia to stay at a Lewiston motel. Arrasmith arrived the following night and was shocked when he saw his daughter the next day: "Her eyes were sunken in. She looked like death." Fearing Ron Bingham might come after Cynthia, Arrasmith asked Lewiston police to place her in "protective custody" at a juvenile facility. A court hearing on the custody order took place the next day. It was a heart-wrenching scene for Arrasmith. "They brought her into court in handcuffs and leg cuffs," he recalls. "I kept thinking, 'What must this girl be thinking: An adult raped me, and I'm the one locked up.' " Cynthia was given a place in a juvenile facility for two weeks. On May 9, Arrasmith went to the Asotin County sheriff's office. "I couldn't believe [they hadn't acted]," he says. "They knew about these rapes two weeks before. I would do whatever I could to put Ron Bingham behind bars."

Over the next week, Arrasmith tracked Bingham's movements. He gave a sheriff's captain the names and addresses of people who hung out at the Bingham's house, people he believed could help their investigation. "I kept thinking, 'Any day now, they're going to pick him up,' " Arrasmith says. When they didn't, he decided to confront the Binghams himself. "I told Ron point blank, 'If these allegations are true, I'll be back with the sheriff.' "

Bingham, he says, pointed an imaginary pistol at him. "If you come back," Arrasmith claims Bingham said, "you won't be leaving." Around noon on May 17, Rilla Smith was listening to the police scanner in her kitchen when she heard a report about a shooting at the auto repair shop where Ron worked. "I just sort of decided it hadda been Ron who was shot," she says. She hoped Luella, who had set out for the garage earlier, hadn't arrived yet.

A few minutes later, Arrasmith parked his pickup in front of the Clarkston police department and quietly gave himself up. His trial could take three to four weeks. Defense attorney Craig Mosman is expected to call a number of the witnesses who say the Binghams abused them, and the police clearly will be on trial too. But prosecutor Denise Rosen seems determined to make Arrasmith an example. She has resisted offering a plea bargain, calling the shootings "a willful, deliberate act." Yet Arrasmith is confident, he says, that a jury will never convict him. "I'm not afraid," he says. "I don't think you can gather 12 people who won't know what's going on here."