On the night of November 9, 2003, 20-year-old Joshua P. Dyer was shot once in the forehead and killed outside his Portland, Maine, apartment. The shooting grew out of a drug transaction earlier that day in which Dyer purportedly bought cocaine from Pedro Santiago and, according to Santiago, left a payment $140 short before fleeing the scene.

Prosecutors said Santiago returned later that evening armed with a 9-millimeter handgun and shot Dyer in what they described as an execution-style killing motivated by the money dispute. Santiago, then 30, was arrested and charged with murder. At the six-day trial in Cumberland County Superior Court, the defense said Santiago acted in self-defense, testifying that Dyer drew a gun first and that Santiago’s weapon discharged accidentally during a struggle.

Who in Portland at the time might have seen either the daytime transaction or the late-night confrontation and can add details about what happened?