California courts had been divided on the question of whether mere words could be adequate provocation for nearly a century when Valentine was decided.

The 1857 case People v. Butler was the earliest case that applied the traditional categorical test for adequate provocation, relying on the Crime and Punishments Act of 1850, which was based on traditional common law principles.

[1][2][3] Beginning with People v. Hurtado in 1883, a second line of cases had taken a broader approach by allowing juries to decide whether certain facts fulfilled the requirement of adequate provocation.

The California Supreme Court's decision in Valentine resolved this split in favor of the broader approach.

A jury trial found Valentine guilty of first-degree murder, and he was convicted and given a life sentence.