PASCO, Wash. -

A 40-year-old Pasco, Wash., woman earlier convicted of first-degree murder in the fatal shooting of her mother has been sentenced to 45 years in prison.

Franklin County Superior Court Judge Cameron Mitchell called Tashia Stuart's action "a very heinous, permanent crime" when he imposed sentence Wednesday.

The woman had claimed she acted in self-defense when she fatally shot Judy Hebert inside her mother's home in March 2011.

The Tri-City Herald reports that Stuart's then-7-year-old daughter was in the home when her grandmother was killed.

Prosecutors said Stuart had been planning to kill her mother for a few weeks.