Athina Sumi Rivera

Athina Sumi Rivera was sentenced to 16 years in prison Thursday for stabbing her mother to death in September 2015 at the senior living community where she lived.

As McKnight’s Senior Living previously reported, police officers found 61-year-old Margaret Yamaguchi lying on the floor of her room at Atria Covina in Covina, CA, with numerous stab wounds. She was pronounced dead at the scene.

Rivera pleaded guilty to second-degree murder and using a deadly weapon, a knife, on Thursday, according to the Los Angeles County District Attorney’s Office.

Rivera, now 44, was staying in her mother’s room the night of the crime and stabbed her in the middle of the night, according to Deputy District Attorney Lauren Guber, who prosecuted the case. During the attack, an emergency call was made from the room, Guber said, and when community staff members entered the room, they discovered Yamaguchi bleeding heavily.

Initially, Rivera was charged with first-degree murder and faced a possible maximum sentence of 26 years to life in state prison.