Two authors tell the NBC10 Investigators they believe they’ve solved one of Philadelphia’s oldest and most notorious cold cases.

On February 25, 1957 police discovered a young boy beaten, stuffed in a card board box and abandoned in the woods in the city’s Fox Chase neighborhood.

The boy was dubbed “the boy in the box.” Today his grave reads “America’s Unknown Child.”

The details of the cold case chilled Philadelphia. Putting a name on the boy’s grave is something that frustrated generations of police investigators.

“To put a name on the child’s grave and to solve the case, it’s the ultimate in police work,” Philadelphia Police Sergeant Bob Kuhlmeier said.

Kuhlmeier is the third generation of Philadelphia police detectives to lead the case.

In 1998, police exhumed the boy’s body and took a DNA sample from a remaining tooth.

The two authors – one from Los Angeles, and another from outside New York, say they believe they’ve traced the boy’s family to Memphis, Tennessee and need his DNA to prove it.

While researching separate books, they say they've paired two tips together: one from a woman claiming her mother bought and killed the boy; the other from a Philadelphia man who told the authors his family rented a home to a man who sold his son.

They took a DNA sample from who they believe to be the boy’s brother.

“The only way I’m going to find out if it’s the child is with the DNA evidence. Scientific evidence,” New Jersey based author Lou Romano said.

“It makes the most sense when you look at all the facts,” Los Angeles based author Jim Hoffman said.

Dr. Greg McDonald reviewed pictures of the boy, his potential brother and potential father.

McDonald is Philadelphia’s former assistant medical examiner and the current Montgomery County deputy medical examiner.

He said forensic experts will use pictures to judge if further laboratory analysis is required.

“There are some similarities to these pictures,” McDonald said. “Enough similarities that I think it’s worth further investigation through further laboratory tests.”

Dr. McDonald said the three men appear to share traits that could point to a genetic match.

Sgt. Kuhlmeier and his colleagues worked 280 homicides in 2015. He said they have to work fresh cases first leaving little time to chase leads in a 59 year old cold case. He called the author’s tip “average” and said before comparing any DNA police would need to confirm the timeline that led the authors to their conclusions.

“We’re going to investigate further is what we’re going to do,” Kuhlmeier said.