In the early morning hours of February 7, 2009, 19-year-old Keith M. Leverone was found in the parking lot of a convenience store at 662 Belmont Street in Brockton, Massachusetts, with a fatal gunshot wound to the head. Police had responded to multiple 3:11 a.m. calls reporting shots fired and pronounced Leverone dead; the Office of the Chief Medical Examiner ruled his death a homicide.

Investigators said a physical altercation occurred outside the store before the shooting. A man later identified as Joao Teixeira was seen arming himself with a handgun, and shortly afterward Leverone was shot in the parking lot. Teixeira was arrested and, at a 2012 trial, was convicted of Murder in the First Degree by deliberate premeditation and Unlawful Possession of a Firearm; he was sentenced to life in prison without the possibility of parole.

What details about the events that night or the people involved might still help clarify how the confrontation escalated to lethal violence?