(NewsNation) — Boulder, Colorado, police are looking into new possible “persons of interest” in the JonBenét Ramsey case, The Messenger is reporting.

While law enforcement is far from making an arrest, there are “several people” on their radar, a police source told The Messenger.

“We are seeing if any of them are the key to solving this case,” the source said, according to the news outlet. “Time will tell if we get the answers we need. This is a marathon, not a sprint.”

Six-year-old Ramsey was found dead in the basement of her home on Dec. 26, 1996. Several hours before, her mother had called 911 to say her daughter was missing and that a ransom note was left behind.

While Ramsey’s death was ruled a homicide, no one was ever prosecuted.

However, investigators in Boulder are still looking into the case. Last year, Boulder Police put out a press release saying the department has followed up on “every lead” that has come in, including more than  21,016 tips, letters and emails. Investigators have traveled to 19 states to interview or speak with more than 1,000 individuals, police said in May 2022.

“We have a shared goal to bring justice — and hopefully some peace — to JonBenét’s family and everyone who was impacted by her loss,” Police Chief Maris Herold said at the time. “Our investigation with federal, state and local partners has never stopped.”

Police started using new DNA technology to test at least five pieces of previously unexamined evidence, but The Messenger reports that it’s not clear if this is what led to the new persons of interest.

In an email to NewsNation, a Boulder Police spokesperson said they are unable to give any interviews or comment on specific aspects of the case as it’s an “open and active investigation.”

Tyler Wornell contributed to this report.