Just past 10 p.m. on a summer night, attorney Cheryl Wattley is standing near a quiet street in West Dallas, reconstructing an old crime.
It's a moonless night. One street light and one porch light from a nearby house illumine the scene, nearly identical conditions to the night 30 years ago, when a young man was left to die on the street not too far from here.
Wattley points toward a man standing under the street light, a private investigator named Daryl Parker, as he positions himself in the alley 40 feet away.
"Can you identify him?" she asks.