HASTINGS, Neb. (AP) — A Nebraska woman has been sentenced to life in prison for killing her boyfriend’s 68-year-old mother.

41-year-old Shelley Casterline, of Guide Rock, was sentenced Monday in Adams County District Court on one count of second-degree murder in the October 2013 slaying of Virginia Barone.

Investigators say the women had been arguing before the death. An autopsy shows Barone was stabbed twice in the back and 20 times in the chest and torso.

Casterline’s 24-year-old son, Andrew Casterline, was found guilty Thursday of first-degree murder and other crimes in connection to the death. Shelley Casterline testified during his trial that her son didn’t stab Barone and only helped her move the body.

Andrew Casterline will be sentenced in December.