America's mercy-killing debate has taken a new twist with the case of a man who killed his wife, only to learn she had been cured of cancer. A Nebraska judge must decide whether to send 76-year-old Vernal Ohlrich to jail after he pleaded guilty to manslaughter. Ohlrich said he shot dead his wife, Phyllis, 74, in her hospital bed last October because they both thought she was dying of colon cancer. Doctors had told Ohlrich that his wife's cancer had spread and was terminal, but an autopsy showed no signs of cancer in her body. An investigation is under way to determine whether doctors got the diagnosis wrong, or whether Ohlrich misunderstood what they told him. His lawyer is also calling the autopsy's findings into question. What is certain is that Ohlrich grew frustrated at seeing Phyllis suffering from weeks of crippling back pain - which she believed was a recurrence of her cancer. Earlier last year, she was operated on to remove the cancer, and also had chemotherapy. When she was readmitted to hospital, she told her husband she wanted to end it all. 'I was told by doctors that she should call her children home because she was not going to make it through the night,' Ohlrich said this week. 'She said she wanted to die several times.' He said that after shooting his wife in the head, he tried to shoot himself, but the gun jammed. 'I wanted to go with her. I would have, if the gun hadn't misfired.' Prosecutors initially charged the defendant with first-degree murder, but allowed a plea bargain on condition they recommended the judge sentence him to at least some time in jail. 'That is the problem with so-called mercy killings,' said local county lawyer Daniel Werner. 'I'm convinced Ohlrich believed she was in imminent threat of death from cancer. He was wrong.' The case comes as the father of the mercy-killing movement, Dr Jack Kevorkian, once again faces the threat of imprisonment. He is being prosecuted for administering a lethal injection to a man who asked to be killed to relieve him of the pain of suffering from Lou Gehrig's disease. Kevorkian dared Michigan authorities to charge him with murder, saying he wanted a definitive court ruling to settle once and for all the issue of euthanasia, which remains illegal in nearly every state.