LOS ANGELES (CBSLA.com) — An 18-year-old woman was convicted of first-degree murder Monday in the 2010 stabbing deaths of her grandparents at the couple’s Rosemead home.

Sophia Janalisa Cristo was 14 at the time of the killings of Jack Bezner, 71, and his 64-year-old wife, Susan, who were found dead in their bed Aug. 9, 2010, with dozens of stab wounds. She was tried as an adult, but is not eligible for the death penalty because of her age when the crime was committed.

Cristo faces life in prison without the possibility of parole when she is sentenced April 22.

Her boyfriend, Rodolfo Lopez, 25, was also charged with murder and is being tried separately.

Jurors deliberated for little more than a day before finding Cristo guilty of two counts of first-degree murder. The panel also found true allegations of lying in wait and multiple murders and that Cristo used a knife to kill Susan Bezner, who was stabbed 112 times. Jack Bezner was stabbed 47 times and had defensive wounds, prosecutors said.

Deputy District Attorney Scott McPheron said Cristo was the mastermind of the crime and she had confessed that she and her boyfriend had killed the couple.

The pair were arrested two days after the killings in Horizon City, Texas, after detectives were told they might be headed there in the Bezners’ missing Nissan SUV.

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