PONTIAC, Mich. — A 75-year-old Detroit-area woman who killed her grandson expressed remorse Thursday but repeatedly accused his parents of dumping a troubled boy at her doorstep during a desperate, emotional plea to avoid a prison sentence that likely means death behind bars. The judge wasn’t swayed, sending Sandra Layne away for at least 22 years and capping a wrenching case that revealed family strife, adolescent rebellion and fatal consequences. Joanthan Hoffman was shot six times, including twice in the back, last spring in Oakland County’s West Bloomfield Township. Layne, a former teacher and real estate agent, said she shot him out of fear during a physical altercation, but a jury in March rejected her claim of self-defense and convicted her of second-degree murder. 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 d ...