There may be a way to identify the killer of a woman jogging in New York City this past summer. However, the method is not used in New York, Newsday reported Monday. Police have yet to make an arrest in the case of Karina Vetrano, who was found dead nearly four months ago near her home in Howard Beach, Queens.

Some forensic science experts and authorities believe that the controversial method known as “familial searching,” which identifies people in the DNA database who are related to an unidentified suspect, can be used to find Vetrano’s murderer. An analysis of the suspect’s Y chromosome and probability rankings are used to find relatives of the suspect in the state DNA database.

Although the method is not used in the state of New York, the father of the victim, Phil Vetrano, wants authorities to employ it to find whoever is responsible for his daughter’s death. “I am going to stop at nothing to have this done,” he said.

“This is the most comprehensive DNA investigation we have done,” NYPD Chief of Detectives Robert Boyce said through spokesman Stephen Davis. “We have done everything we reasonably can do in terms of trying to get expanded DNA out of here.”

Familial searching allows authorities to identify the offender by finding siblings or parents with similar DNA, Independent reported. From there, an investigation is done to find a suspect. Familial searching is not considered evidence, it is an intelligence tool that is helpful in cases that involve sexual assault, serial offenders and murders.

The search is confined to immediate family and does not extend to identifying an aunt or uncle of the suspect. In that case, the person would only share a quarter of the accused’s DNA. Familial searching is used in the Netherlands and the United Kingdom as well as in nine states, including Virginia, California, Michigan and Texas.

Vetrano was initially reported missing by her father after failing to return home from her afternoon run on Aug. 2. Her father then contacted authorities, which found her lifeless body dragged off of the local running trail, badly beaten and sexually assaulted.

Phil Vetrano previously stated that it would be a struggle to get through the holidays without his daughter. “I’m going to stay in the house. I’m going to treat it like a regular day. No celebration, no festivities. Probably just me and [wife] Cathy. I’m going to probably be [spending time] alone,” he stated.