The fitness regimen and the plan to move out of state with her husband to be closer to their son's family ended tragically when four pit bulls attacked, biting her more than 150 times. On Friday, the dogs' owner saw his future plans evaporate when he was sentenced in Los Angeles County Superior Court to 15 years to life in prison.
The rare second-degree murder conviction in a dog mauling had come because Alex Jackson repeatedly ignored complaints about his dogs from horseback riders, neighbours and a postman. Prosecutors said he was well aware of the danger they posed and did nothing about it.
Devitt, 63, hardly stood a chance when the dogs leaped over Jackson's fence and attacked her in May 2013, on the home stretch of her two-mile walk in the high desert town of Littlerock, about 60 miles northeast of Los Angeles.
She was unarmed, didn't have a phone and no one was nearby. By the time help arrived, she had been savaged from head to toe and an arm was severed. She died from blood loss.
"Her story shouldn't have ended in such a horrific way," her husband, Ben Devitt, said as he overcame emotion to speak in court.
The birth of their grandson four years ago had altered the couple's retirement plans. The needed to be healthy, so they started walking. It went from occasionally to daily.
Devitt's last image of his wife was as she worked out on an elliptical training machine when he left to work the graveyard shift at a trucking company.
He knew nothing of the attack when he returned the next morning. Sheriff's deputies showed up and asked him to identify his wife's iPod. She hadn't been carrying identification and was listed as Jane Doe in the hospital.
Jackson, 31, was arrested when deputies searching for the dogs discovered a marijuana-growing operation in his house. He was later charged with murder when tests found Devitt's DNA in his dogs' bloody coats. The dogs were put down.
A murder charge for a killing by dogs is rare and applied when someone did something so reckless they knew it was dangerous enough to kill someone.
A San Francisco woman was convicted of second-degree murder in the fatal mauling of her neighbour in the hallway outside her San Francisco apartment in 2001. A Michigan couple faces trial for second-degree murder in the deadly mauling of a jogger by their two dogs this summer.
In Jackson's case and others like it, there was a record of complaints that the dogs were dangerous.
"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.
The Devitts bypassed Jackson's house by a quarter-mile because the racket from the dogs interrupted the peacefulness of their walk, but they had never had an incident with the animals.
But nine other witnesses testified about frightening encounters. One equestrian had offered free fencing to Jackson, but he did not accept the help.
Jackson did not speak during sentencing. Defence lawyer Al Kim, who said Jackson will appeal, conceded at trial that Jackson was a drug dealer, but he never intended any harm by the dogs he loved. He argued the judge should consider probation because of Jackson's nonviolent criminal record.
Judge Lisa Chung, citing Jackson's arrest record and probation problems, rejected that argument. She also rejected a prosecution request to tack on an additional nine-year term for drug convictions and a firearms charge. Instead, she sentenced Jackson to seven years for those crimes to run concurrent with the murder term.
He will be eligible for parole after serving 15 years.
Jackson's older brother, Vincent, said the killing had taken a heavy toll on his family and his brother felt "absolutely terrible."
"This has definitely been something that's been a life-changer for all of us," he said.
So, too, for Devitt. He retired after his wife's death — sooner than he had expected — and moved to Washington.
"One of the compelling reasons for selling the house and moving was that everything she planted in that yard was withering away and turning brown under my care and it was distressing me," he said.
He said he supported the murder charge and travelled back to Los Angeles County to speak because he wanted to let other dog owners know they "can't be terrorizing their neighbours."
As Devitt waited for an elevator, Vincent Jackson stepped forward, offered his hand and said he was sorry for his loss. As they shook hands, Devitt said he was sorry for Jackson's loss.