A detailed timeline frames the killings in Grantsville, Utah, on January 17, 2020. The attack began about 1:00 p.m. when 16-year-old Colin Jeffery CJ Haynie shot and killed his mother, 52-year-old Consuelo Alejandra Haynie, and his youngest sister, 12-year-old Milan. He then waited for other family members to come home.

Between about 2:00 and 5:00 p.m. the 15-year-old sister Alexis arrived and was also shot and killed. Matthew James Haynie, 14, returned at about 5:17 p.m. and was fatally shot once in the head. The rampage continued until about 6:15 p.m., when the boys’ father, Colin Haynie, returned; CJ shot him in the leg but the father wrestled the handgun away. A neighbor drove the wounded father and son to a hospital and later contacted police after CJ confessed.

CJ Haynie was arrested and charged as an adult with four counts of aggravated murder, attempted aggravated murder and related firearm offenses; prosecutors said he told his father he intended to kill everyone in the house but himself. Anyone who knew Matthew or the family, or who has information about that day, is asked to come forward.