San Francisco ? Citing a lack of evidence, a judge tossed out Marjorie Knoller’s murder conviction Monday in last year’s dog-mauling death of a neighbor. He also sentenced Knoller’s husband to the maximum four years in prison.

Knoller, 46, could have faced 15 years to life in prison for murder. Like husband Robert Noel, she now faces up to four years for involuntary manslaughter and having a mischievous dog that killed someone.

The judge’s decision stunned friends and relatives of the 33-year-old victim, Diane Whipple. Knoller’s sentencing was delayed until at least July 15 so prosecutors can argue that her second-degree murder conviction should be reinstated.

“We have not yet given up on our chance of convincing the judge that the murder charge is appropriate,” Dist. Atty. Terence Hallinan said.

Superior Court Judge James Warren said that Knoller and Noel are “the most despised couple in this city” but that the evidence did not support the murder conviction.

He said Knoller had no way of knowing her dogs would kill someone when she left her apartment Jan. 26, 2001.

“There is no question in this court’s mind that in the eyes of the people, both defendants are guilty of murder,” Warren said. “In the eyes of the law, they are not.”

Whipple, a college lacrosse coach, was attacked by the couple’s two huge Presa Canario dogs in their apartment hallway last year. The judge called the dogs “a canine time bomb that would at some inevitable point explode with disastrous consequences” even as he threw out Knoller’s conviction.

“I’m in shock,” said Sharon Smith, Whipple’s partner, who shed a tear as the judge ordered a new trial for Knoller.

If Warren doesn’t change his mind and his decision stands, prosecutors will have to consider whether they can retry Knoller for murder without violating her constitutional right against double jeopardy. She was convicted of manslaughter for the same crime.

Knoller was walking the dogs just before they attacked Whipple her husband was out of town and testified that she tried to throw herself between the animals and her neighbor. The judge threw out the murder conviction despite saying he did not believe much of Knoller’s testimony.

“I cannot say as a matter of law that she subjectively knew that day that her conduct would cause death,” he said.

Warren also pointed out that Noel was not charged with murder and that Noel, in the judge’s view, was more culpable than his wife.

The judge said Noel knew his wife could not control the dogs, each of which weighed more than 100 pounds, and knew they would have to be walked at some point that day. The burly Noel had been unable to control the animals at least twice previously, the judge noted.