"It's been an interesting year," said Carter, who lives in Bella Vista with his wife, Tracy. "It's been pretty crazy. You go from not having any real blood relatives to having an expanded family.
"You had a lot of people you didn't know existed, and it's a strange feeling."
Carter's biological mother, Charlotte Moriarty, was admitted to a psychiatric hospital after being discovered inside a stranger's house with the infant, People reported. A few days later, Moriarty, who would be 66 now, checked out of the hospital against medical advice, leaving her son in protective care. She has been missing since.
Among the tidbits Carter said he has learned about his life over the past 15 months:
* His birth name was a bit more exotic than his adopted moniker - Marx Panama Moriarty Barnes, to be precise. Carter said he learned recently from his biological father, Mark Barnes, that he was named after both Karl Marx and Carter's godfather, whose nickname was Panama.
* Before entering the hospital, Moriarty told authorities that the child's name was "Tenzin Amea," and she falsely stated that his father was native Hawaiian. Baby Marx became a ward of the state, and he was moved to an orphanage 30 miles from his home.
* His father, in fact, was a white man from California living in Hawaii, who reported his son and girlfriend missing three weeks after their July 21, 1977, disappearance. Before Carter's birth, Moriarty - described in the People story as a "free-spirited artist" - had left home and returned on other occasions, which kept Barnes from reporting her missing at first.
"I spent about a year-and-a-half going crazy driving around the island," Barnes told People. "It was rough."
Carter was adopted at age 4 by military man Steve Carter and his wife, Pat, who eventually moved to Medford Lakes, Burlington County.
Carter's curiosity about his background began, he said, after he read about the case of Carlina White in January 2011. White, of Atlanta, solved her own kidnapping when she found images of herself on missingkids.com.
Carter, a Penn State grad who was always suspicious that his birth certificate was created when he was a year old, followed suit.
"Having a birth certificate created a year after you are born leaves a lot of questions about your early years," Carter said.
On missingkids.com, Carter found photos of baby Marx and computer-simulated pictures of what the missing child might look like at age 28.
"When I saw the baby picture, I pretty much knew it was me," he said. "It was pretty surreal. The picture almost guaranteed that it was me, that I did have actual blood relatives who were looking for me."
Carter's wife and adoptive parents urged him to contact authorities. That began a long process that ended in October when his DNA matched baby Marx's.
Carter, who works for a medical-software company, has adjusted slowly to his new reality. He has created a Twitter handle, @MoriartyBarnes, and has spent hours chatting by phone and online with his older half sister, Jennifer Monnheimer, 43, who lives in New Mexico.
Monnheimer, Charlotte Moriarty's daughter who was living with her father in New Mexico at the time of the disappearance, is credited with tracking down her brother, according to People. She persuaded Hawaiian authorities to reopen the case, leading to the composite photos and the case being featured on missingkids.com.
When the two finally talked by phone in February, she told People magazine, "I just wanted to reach through the phone and hug him."
-Daily News staff writer Haley Kmetz contributed to this story.
Contact Regina Medina at 215-854-5985 or firstname.lastname@example.org, or follow on Twitter @ReginaMedina.