On January 5, 1985, four members of the McNamara family were killed at the family ranch in Santa Barbara, California. Victims included Elger and Florence McNamara, their daughter Diane Trenner, and Diane’s 4-year-old daughter Kellin Brooke Trenner. Bodies were found both inside and outside the home, each with multiple gunshot wounds.

Barry McNamara, Diane’s brother and Kellin’s uncle, was arrested at the scene. Neighbors heard screams and gunshots, and a friend of one of the victims placed a call after hearing a loud bang and subsequent screams. Investigators reported the massacre was likely motivated by a family dispute; Barry McNamara told authorities he had heard voices from a television instructing him to kill. He was charged with four counts of first-degree murder, the jury found him sane at the time of the killings, and he was convicted on all counts. The penalty phase was set to determine whether he would receive the death penalty.

What details about the family’s interactions or the days leading up to January 5 might help explain how the dispute escalated to this violence?