Almost four months ago, Karina Vetrano left her Queens home on a jog through Howard Beach. Later that night, her body was found in a marsh less than a mile from her house.

The 30-year-old woman's death has stumped investigators. Though authorities believe Vetrano was strangled and sexually assaulted, and even released a sketch of a witness, no suspect has been identified since the Aug. 2 murder. Her family, meanwhile, has aggressively raised funds online to supplement the $35,000 reward offered by the NYPD and mayor's office. As of Tuesday, the GoFundMe campaign had raised $285,440.

The strongest lead NYPD detectives have to work with is DNA found on Vetrano's body, though it hasn't matched any profiles of convicted criminals in state or national databases.

For some experts, the key to Vetrano's case is a DNA analysis technique not typically applied in New York.

The "familial searching" methodology can identify a partial match to the suspect through the Y chromosome, possibly a sibling, child, parent or other blood relative. New York state, however, primarily uses "partial match" analysis, which fails to find matches for siblings in a majority of cases, experts told Newsday this week.

Familial DNA searching — though controversial — can assist detectives in identifying potential suspects. From there, they can resort to traditional investigative techniques to develop reasonable suspicion and retrieve a DNA sample from a person of interest.

However, officials say that state law is vague on whether DNA searching is legal. According to Newsday, an official at the city medical examiner's office believes state law forbids the method; a spokeswoman for the state Division of Criminal Justice Services said no law exists.

Still, Karina's father Philip Vetrano told the Long Island publication that he intends to raise the issue with police and government entities.

"I am going to stop at nothing to have this done," he said.

The methodology made headlines in recent years, particularly with the conviction of a California serial killer known as the Grim Sleeper. A search of California's DNA database revealed a young man who had recently been arrested in Los Angeles partially matched samples taken from the Grim Sleeper's crime scenes. Detectives were able to narrow their investigation down to that man's father, who was arrested and charged as the serial murderer.

Despite its successes, the method isn't without its criticism. 

In 2009, after the State Commission on Forensic Sciences approved the use of familial searching in criminal investigations, the New York Civil Liberties Union (NYCLU) issued a statement warning against misuse of the method.

“A policy that implicates New Yorkers in a criminal investigation solely because they are related to someone with DNA in the state’s databank is a miscarriage of justice,”  Donna Lieberman, executive director of the NYCLU, said.