20/20 special looks at investigation into murder of 16-year-old Susana Morales

GWINNETT COUNTY, Ga. — On a hot summer night, 16-year-old Susana Morales was visiting her friend’s house when she seemingly disappeared. A tracking app on Susana’s phone showed her walking home, then suddenly going the opposite direction in a car.

Minutes later, her phone registered a crash alert, yet there were no signs of an accident and no signs of Susana at the location.

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After reporting her missing, Susana’s family took matters into their own hands, retracing her steps and uncovering surveillance video just minutes before she vanished.

In a heart-pounding investigation, explosive video tracks detectives — in real time — as they hunt for clues in Susana’s disappearance. Six months later, a critical breakthrough led authorities to Susana and to a piece of evidence that broke the case wide open.

ABC News correspondent John Quiñones speaks to Susana’s mother in the all-new “20/20”episode “Tracking Susana.”

It airs Friday night at 9 p.m. on Channel 2.