Carter, a 35-year-old software salesman, was adopted at age 4 from an orphanage in Honolulu.
On a hunch, he clicked on in hopes of answering the unanswered questions about his origins.
It was there he found an age-progression image made from a photograph of him as an infant.
Carter recognized himself immediately, he said, and contacted the Honolulu Police Department.
"I let them know my info and they ran with it," he said. "They were the ones who did all the legwork" of investigating the case.
Carter then volunteered for a DNA test in February 2011. Eight months later its findings revealed fragments of his story and the name he'd been given at birth: Marx Panama Moriarty Barnes.
His biological father, Mark Barnes, reported him missing more than three decades ago after his mother, Charlotte Moriarty, took him for a walk and didn't return.
Carter says he believes Moriarty put him in the Hawaiian orphanage and told authorities his name was Tenzin Amea.