WHO REALLY KILLED SHARITA RIVERA?

Bad science may have sent Quincy Amerson to prison for life. New crime scene tech could set him free.

- JOHN H. TUCKER

SHAWN HARRINGTON STARTED DOWN THE ROAD BEFORE HIM, his yellow safety vest reflecting any glints of sun the winter sky had to offer. The forlorn street, flanked by woods and a creek and devoid of any lights, had been repaved in the years since the little girl's death, but not much else had changed. Stillness enveloped the terrain, and Harrington grew haunted by how dark it was that early morning-how fearful the girl must have been before the fatal collision. Did she attempt to flag down help while traversing the tight shoulder? He wondered. Did she cower as cars whizzed by with poor headlights? 

Pushing emotion aside, the then-35-year-old forensic engineer and accident reconstructionist from suburban Philadelphia began his customary walk, starting from what he calls the hot zone. Informed by a utility pole from the original police sketch, Harrington pinpointed the westbound-lane location where the girl's body was discovered. Working his way outward, he analyzed small circles of space while photographing everything relevant: photos of the fog line (the line between the lane of a road and the shoulder) where police found a tire impression and blood trail; of the bridge, where a wheel-well liner was retrieved; of the street leading to a small subdivision-the closest sign of life in these central North Carolina backlands 25 miles northwest of Fort Bragg.