A man accused of stabbing his girlfriend to death with a steak knife was found guilty by a jury Monday.

Armando Lopez was found guilty of first-degree murder for killing Marie Mesa in 2012.

Lopez’s attorney had argued his client acted impulsively following an argument with Mesa the night he beat and stabbed her 15 times. The attorney told jurors they should consider Lopez’s crime manslaughter instead of murder.

The state, however, successfully argued Lopez acted with premeditation.

Lopez is scheduled for sentencing Aug. 5. He is not eligible for the death penalty.