A fresh wave of public interest in the 1996 murder of JonBenét Ramsey has heightened expectations for progress in the decades-old case, even as key figures warn that recent leads may be more speculative than substantial. Nearly 28 years after the six-year-old's body was found in the basement of her family's Boulder, Colo., home, interest in the case has once again surged, fueled by the Netflix docu-series Cold Case: Who Killed JonBenét Ramsey.

John Ramsey, now 81, recently disclosed that he received a letter from an unidentified woman who claimed her ex-husband was responsible for JonBenét's death. "Based on all this publicity, recently I got a letter from a lady saying, 'My ex-husband's the killer, and I've kept this inside for as long as I can - please, please call me,'" he told the Daily Mail. The message, he said, stirred cautious optimism. "We reached out to her, but she didn't answer the phone, so I don't know. We've shared it at this point with a private investigator."

Despite initial intrigue surrounding this letter, Joe Berlinger, director of the Netflix series, quickly sought to temper expectations. "Honestly, this lead has been way overblown," Mr. Berlinger said in an email to The U.S. Sun. "Mr. Ramsey did an interview and he just mentioned this in the context of 'yeah, we've gotten some recent activity because of the documentary.' He didn't mean it to be like it was a great lead. They just don't know and not sure who is looking at it to verify it."

The renewed interest also reflects growing public pressure on authorities, who have struggled for decades to find a credible suspect in the killing. Boulder's law enforcement officials have acknowledged the influx of new tips following the Netflix series. Police representatives have told various media outlets that they are applying modern cold case investigative techniques and exploring advancements in DNA technology to determine whether any new clues can break the impasse.

Authorities close to the investigation have expressed guarded optimism. "I'm not sure what it will take to bust it wide open," a source told the New York Post, "but it feels like it's within reach. We're hoping for 2025: this is our year." A second source noted that newly appointed Boulder Police Chief Steve Redfearn has turned his attention to resolving the long-stalled case. "He wants it solved and off the books, and he's assigning officers and resources to solving the murder, which has been a black mark on the Boulder PD."

In the initial stages of the investigation, widespread media attention and alleged mishandling of the crime scene placed intense scrutiny on JonBenét's parents, John and the late Patsy Ramsey, as well as on her brother, Burke, who was nine years old at the time. The family was officially cleared by the District Attorney's office in 2008. Yet doubts linger in the public consciousness, making each new tip a flashpoint of renewed debate.

Mr. Ramsey, however, is no stranger to dashed hopes. Over the years, he encountered numerous false leads, from letters and calls by individuals seeking attention or extortion, to the sensational but fruitless confession of John Mark Karr in 2006. In describing one such interaction involving a caller who claimed to be the killer, Mr. Ramsey recalled looking for "information that maybe he had that nobody else would have." Each time, the trail led nowhere.

Still, Mr. Ramsey remains committed to finding the truth. "It's not going to change my life at this point-I just turned 81-but it'll change my children's lives, my grandchildren's lives," he said. "They need to have this cloud removed, clarified, and an answer. That's why we're pushing so hard to get an answer."