A 9/11 victim's DNA helped identify a murdered girl 21 years after construction workers found her skull at a famous New York club.

The remains of 16-year-old Patricia Kathleen McGlone, last seen in 1969, were found in 2003 at the former site of Steve Paul's The Scene. The venue in the Hell's Kitchen area once hosted stars such as Jimmy Hendrix.

"They were knocking through the concrete floor [and] a skull rolled out," New York detective Ryan Glas told Sky's US partner NBC News. The victim was wearing a ring with the initials PMcG, matching her name, and a 1960s-era Bulova watch, police said.

A plastic toy soldier was also found on her, prompting police to believe the girl, who had been dubbed "Midtown Jane Doe" for two decades, might have had a child. Publicly available DNA records, including those belonging to a 9/11 victim, helped identify the teenager.

"With any investigation, especially a homicide investigation, the first thing you need to have is a name to the victim, because it gives you a starting point," Mr Glas said. "Any little bit of information helps, especially with cold cases." Police say they've managed to discover she was born on 20 April 1953, was Catholic and went to a state-funded school.

Read more:Man convicted of 1994 murder after DNA breakthroughWoman killed and burned 30 years ago identified by police "This is personal for me, because everyone has a daughter, everyone is the child of somebody," Mr Glas said. "You got to get justice for the people that are killed." Both of her parents, who have since died, are not considered suspects, police said..