KNOXVILLE, Tenn. — A former nurse surrendered Thursday on a murder charge in the death of her husband, a district attorney who authorities originally believed was killed when he was trampled by cattle in a farming accident.

Raynella Dossett Leath, 59, was charged in an indictment with first-degree murder and was released on $25,000 bail. She also faces a murder charge in the 2003 death of her second husband.

Dossett Leath's attorney, James A.H. Bell, said she will plead not guilty to Dossett's death, just as she as did to her second husband's death.

When William Edward Dossett died in 1992, officials ruled he was knocked down and trampled by cattle in his pasture.

But questions about whether he was drugged emerged in January during hearings about whether to exhume his body. A medical examiner testified that toxicology reports completed after the district attorney's autopsy indicated he may have died instead from an overdose of morphine.

Dossett had a surgically installed morphine pump to treat pain caused by his terminal cancer, but prosecutors have said the amount of morphine found in his system was so high the district attorney likely would not have been able to walk.

"I hate it has taken so long a period of time to move toward resolution of Ed Dossett's death," said special prosecutor Richard Fisher. "Justice doesn't always move this slow, but at least it is moving forward."

Fisher said he expected to make another request to exhume the body, though he suggested other evidence has been uncovered by cold case investigators at the Knox County Sheriff's Office.

Dossett Leath is accused of fatally shooting her second husband, David Leath, a barber and lifelong friend of first husband. She claims the retired barber committed suicide.

Prosecutors have said there are similarities between the deaths. Leath was found to have painkillers and antidepressants that were not prescribed for him in his system at the time of his death.