Shanna L. McGrath, 42, was shot and killed at her home on Peoria Boulevard in Crestview, Florida, on January 23, 2016. Merrick was shot in the head outside the home after an argument; Shanna was shot as she tried to call 911; Kevin McGrath was killed during a gunfight inside the house.

Two family dogs were also harmed, with one dying at the scene and another seriously injured. Jacob Langston was arrested and charged in connection with the killings.

What information might help explain how the dispute began or link others who were present to the events that day?