The state Supreme Court has declined to review the second-degree murder conviction of a former Littlerock resident who owned four pit bulls that fatally mauled a woman nearly three years ago.

Alex Donald Jackson was sentenced in October 2014 to 15 years to life in state prison after being convicted for the May 9, 2013, dog attack on Pamela Devitt, a 63-year-old Palmdale grandmother who was walking in the area as part of an exercise routine.

Jackson was also convicted of three drug-related charges—cultivating marijuana, possession of marijuana for sale and possession of a controlled substance—but he was acquitted of a single charge of assault with a deadly weapon involving an alleged run-in with a horseback rider in January 2013.

In April, a three-justice panel from California’s 2nd District Court of Appeal rejected the defense’s challenge to the sufficiency of the evidence in Jackson’s case.

“Appellant knew his dogs were jumping his fence and attacking passersby,” the appellate court panel found in a 14-page ruling. “As an owner of animals with dangerous propensities, appellant had a duty to exercise reasonable care in keeping his dogs from jumping the fence, and his failure to do so caused the death of another person.”

Authorities said Devitt sustained about 200 puncture wounds in the dog attack, which began when she was walking about one-eighth of a mile from Jackson’s home.

A motorist’s pickup truck was also chased by the dogs after the motorist—who called 911—honked her horn in an effort to stop the dogs from attacking Devitt, Deputy District Attorney Ryan Williams said after the verdict.

The prosecution wrote in a sentencing memorandum that Jackson kept the dogs and a shotgun to guard a drug operation at the house.

During Jackson’s sentencing hearing, the victim’s husband, Ben, said he and his wife had begun walking regularly after their grandson’s birth.

“First of all, four years ago, our grandson was born and that kind of gave us a little different opinion about our elderly years,” he said. “The walking went from occasional to routine to daily.”

Ben Devitt said he had moved to Washington state after his wife’s death, saying he couldn’t bear watching all of the work she had done in their yard “turning brown and withering away.”

“Her story should not have ended in such a horrific way,” he said.

During the trial, Jackson testified in his own defense, telling jurors that he felt “terrible” about what had happened. DNA testing confirmed that dried blood from the victim was found on four of Jackson’s dogs, who were found locked in a garage, authorities said.

The four dogs involved in the attack on Devitt were euthanized, while four other dogs found on the property were adopted by other families, according to the prosecutor.