US police announced on Thursday that they had used modern DNA testing and genealogical analysis to identify a boy found dead in a cardboard box in Philadelphia more than 65 years ago.
The case of the "Boy in the Box" – the subject of a 2008 book – is one of the East Coast city's most notorious unsolved murders.
At a press conference, Philadelphia police commissioner Danielle Outlaw named the child as Joseph Augustus Zarelli.
His severely beaten body was found wrapped in a blanket inside the box in a wooded area of Philadelphia in February 1957.
"The boy appeared to be malnourished, and his body bore the signs of recent and past trauma. In his very short life it was apparent that this child experienced horrors that no one, no one, should ever be subjected to," Outlaw told reporters.
An autopsy concluded that the boy was aged between four and six but nobody ever came forward to claim the body, and hundreds of tips and leads failed to identify him.
Zarelli was initially buried in a potter's field, a burial site for unknown or unclaimed people.
His remains were exhumed in the late 1990s and reinterred in a cemetery alongside a gravestone that reads "America's Unknown Child."
DNA testing was done then but failed to identify the boy, police captain Jason Smith told reporters.
Police exhumed his remains again in 2019 following the development of new forensic techniques, said Smith.
The test results were uploaded to DNA databases and analysed by genealogists, who were able to help police identify relatives on the child's maternal side, Smith added.
The genealogists confirmed Zarelli's birth mother, and detectives found a birth record for a child of hers born in 1953.
The record also listed the name of the father. DNA testing of relatives then confirmed the father's identity, making genealogists certain that Zarelli was born on January 13, 1953.
Smith did not identify the parents but said the child has "a number of siblings" who are still alive.
Police hope the breakthrough in the cold case will help officers identify a suspect.
"This is still an active homicide investigation and we still need the public's help in filling in this child's life story," said Outlaw.
The mystery of who he was had "haunted" the law enforcement community for decades, she said. (AFP)