Sandra Layne, 75, was convicted of second-degree murder of her grandson, Jonathan Hoffman, 17, who was living with her at the time of his death.
In closing statements Monday, Prosecutors asked for jurors to look past the emotions of the case, in which Layne admitted to shooting Hoffman on May 18, but claimed self defense.
After Hoffman failed a court-ordered drug test, Layne confronted him, and things got physical. As Hoffman made a frantic phone call to police, Layne retrieved a Glock handgun she had recently purchased and fired it 10 times.
"Ow! No grandma ... I just got shot again ... ow, my stomach," Hoffman can be heard saying in a recording of the 911 call.
"She walked away from him, by an exit, ignored the cellular phone in her pocket, and returns back up the stairs and shoots him again," said Oakland County prosecutor Paul Walton. "That is deliberate. That is murder."
The judge had instructed jurors to consider first- and second-degree murder, as well as manslaughter, involuntary manslaughter and acquittal.
Second-degree murder carries a potential sentence of any term up to life with a chance of parole.
Martin Bashir resigns from MSNBC over Sarah Palin comments
Exploding whale video goes viral on Internet