A pit bull owner convicted of second-degree murder after his dogs fatally mauled a woman was sentenced Friday to 15 years to life in prison.

Alex Donald Jackson, 31, was convicted in Lancaster, Calif., last month in the death of Pamela Devitt. The 63-year-old retiree was taking a morning stroll in the high desert town of Littlerock when four of Jackson's dogs leaped over a fence and attacked her in the street.

She was alone, didn't have a phone and no one was nearby. By the time help arrived, she had been bitten 150 to 200 times from head to toe and an arm was severed. She died from blood loss.

Pamela Devitt was mauled to death by four pit bulls in the high desert neighborhood of Littlerock in Palmdale, Calif. (Associated Press)

Jackson was initially arrested when deputies searching for the dogs discovered a marijuana-growing operation in his house. He was later charged with murder when Devitt's DNA was found on his dogs' bloody fur.

A murder conviction for a killing by dogs is rare.

The mauling of Diane Whipple in the hallway outside her San Francisco apartment in 2001 led to her neighbour's second-degree murder conviction.

A Michigan couple is facing trial on second-degree murder charges for the mauling death of a jogger in July by two cane corsos, an Italian mastiff-type breed, near their home about 72 kilometres outside Detroit.

'Nearly psychopathic disregard'

The theory behind such cases is that the accused did something so reckless they had to know it was dangerous enough to kill someone — even without intending harm.

"His actions in this case show that he has a nearly psychopathic disregard for the lives and well-being of others," Deputy District Attorney Ryan Williams said of Jackson in his sentencing memo.

Prosecutors in Los Angeles County Superior Court sought a term of 24 years to life in prison for the murder and convictions on weapon and drug charges. The dogs guarded Jackson's pot-growing operation and he knew the animals were dangerous, Williams said.

In Jackson's case and others like it, prosecutors have said neighbours and others complained that the owners' dogs were vicious or dangerous and that the owners didn't do enough to control the animals.

The Devitts, who passed through the area during their walking routine, had never had a problem with the dog, Williams said.

'Nail in the coffin'

But nine other witnesses, including several horse riders and a postal worker, testified about seven frightening encounters. One equestrian had offered to provide free fencing and help Jackson put it up to keep the dogs on his property, but Jackson did not accept the help.

Defence lawyer Al Kim said Thursday that the "nail in the coffin" for Jackson was that the number of other incidents made it hard to argue that he wasn't aware of the danger the dogs posed.

At trial, Kim conceded Jackson was a drug dealer, but also said he was a dog lover who took in strays that reproduced. While he should have kept closer watch of them, he never intended to hurt someone.

"He's not the evil dude he's being made out to be," Kim said. "He feels horrible about this. He's contrite."