Ruth Langlos' nightmare began on Feb. 2, 1976 when her husband, John, a psychologist, was found dead in his office in Downey, Calif., an L.A. suburb. John Langlos' head was cut, his eyes were bruised and the walls near his body were splattered with blood. His wallet, checkbook and necktie were missing. Ruth Langlos received a second stunning jolt two weeks later when she read the coroner's report: John's death, it said, was the result of natural causes, probably a heart attack.

Outraged, Ruth Langlos launched what ultimately became a one-woman crusade to prove her husband had been murdered and to find his killer. It took seven frustrating years and a willingness to deal with grisly, heartbreaking details, but Langlos, now 64, has prevailed.

Shortly after the murder, she thought the case was as good as solved when Oakland police arrested a man who had used her husband's stolen credit cards. The man, Eugene Clarence Hartman, now 55, was a psychologist who had worked with her husband and, the police say, had books at home describing how to adopt a false identity and start a new life. Still, the D.A.'s office, lacking a death certificate that said "homicide," refused to prosecute for murder. "The deputy D.A. was giving us all these hypotheses, like that Hartman came into Dr. Langlos' office, found him dead, and merely stole the wallet and checkbook," says Downey police officer Mike Westray. "They always think up defenses. They're trying to reduce their chances of losing. It makes their conviction rate look good." Instead of murder, Hartman was convicted of using a stolen credit card and forging a check and served 36 days in jail.

Undeterred, Langlos hired a forensic pathologist, who exhumed her husband's body and determined that he died "by strangulation or by a blow to the head." With that she tried to take the coroner's office to court, but a judge denied the writ, ruling that the initial autopsy had been done properly.

Langlos' cause received a needed boost in 1978 when the state of California, which pays a nominal sum to victims of crimes or to their survivors, decided to pay her—thus, in effect, agreeing that a crime had been committed. Armed with that decision, Langlos sued her husband's insurance company for double indemnity. The insurance company, in response, hired its own pathologist, who also concluded her husband had been killed.

Even after that Langlos had to appeal to state government officials for four more years. "I got to the point where I had no more money and my sons had to start paying some of my bills," says Langlos, who figures she spent $50,000 on her crusade. "I had also been hospitalized twice for depression." In 1982 newly elected California Governor George Deukmejian ordered a coroner's inquest to review the evidence, and the eight-member panel found unanimously that John Langlos had been murdered.

Last December, Hartman was tried and convicted of second-degree murder. At his sentencing, Langlos was allowed to speak before the court. "I received a life sentence the day you killed my husband," she said, looking directly at Hartman. "You took John away from me permanently. I will receive no time off for good behavior. I will not get out on probation or go on parole. It was shattering to lose the man I dearly loved." Hartman's sentence: five years to life.

Meanwhile, Ruth Langlos' persistence in the face of seemingly impossible odds has become the stuff of legend among local law enforcement officials. Says Downey Police Captain Pete Stone, "I've told Mrs. Langlos that if she ever reads that anyone has done away with me, I want her to be on the case."