PONTIAC, Mich. — A 75-year-old Detroit-area woman convicted of murder in the fatal shooting of her teen grandson was sentenced to at least 22 years in prison Thursday, despite a plea from her lawyer that she may not survive a long stay.

Sandra Layne got a minimum sentence of 20 years for second-degree murder, along with a mandatory two-year sentence for using a gun to kill 17-year-old Jonathan Hoffman.

Hoffman was shot six times, including twice in the back, last spring in Oakland County’s West Bloomfield Township. Layne said she shot him out of desperation during a physical altercation, but a jury in March rejected her claim of self-defense.

Prosecutors said there were no signs of Layne being injured by Hoffman. A recording of a 911 call shows him being shot again while pleading for help – a critical piece of evidence that jurors played over and over during deliberations.

Hoffman was living with his grandmother during his last year of high school while his parents lived in Arizona where a daughter was being treated for a brain tumor. He had a history of drug use and had tested positive for synthetic marijuana on the day of the shooting. Layne claimed he feared flunking probation and demanded money and a car to leave the area.

Prosecutors, however, said Hoffman was wearing just shorts and socks when he was killed and had made plans to see a friend that night, not flee.

Hoffman’s father, Michael Hoffman, said in a letter read aloud to the judge by Assistant Prosecutor Paul Walton that Layne “put on her war paint and came in gunning for my boy.” Hoffman, who was not in court Thursday, said he was in Arizona with his 16-year-old daughter, Jessica, who is recovering from a brain tumor. She “has a hole in her heart to match the hole in her head.”

Layne’s daughter, Jennifer Hoffman, told Judge Denise Langford Morris: “Do not show mercy. She showed no mercy when she planned, stalked and murdered my son in his bedroom. Sandra Layne is pure evil and if given the opportunity would surely kill again.”

Layne, sobbing and wearing orange jail clothes with chains and handcuffs sagging on her slight frame, told the court: “I’m sorry for what I did. I apologize to everyone I’ve hurt, everyone … Sorry is too small a word.”

Layne sobbed deeply as she continued her rambling address to the judge. She repeatedly blamed the parents for not taking Jonathan back to Arizona and said her grandson’s drug use made him unmanageable for an elderly woman.

“I don’t know what else to say,” Layne said. “… I don’t want to die in jail.”

Layne will get credit for 11 months served in jail. Any release from prison after serving the minimum sentence would be determined by the Michigan parole board.