JonBenét Ramsey Murder: Boulder PD Re-Testing DNA Evidence With Newer Technology

Investigators have finally vowed to retest DNA samples tied to the unsolved killing of JonBenét Ramsey ... days after the late pageant star's brother made an impassioned plea.

Boulder Police Chief Steve Redfearn told reporters this week that officials are "retesting things that were tested 30 years ago with newer technology."

Boulder County DA Michael Dougherty added ... "Chief Redfearn and I are more hopeful now than we have been in the past because of the advances in the investigation and the advances in technology. And I say that based on just how DNA has progressed over time."

Dougherty admitted that while mixed samples of DNA need to be untangled in a process that could potentially destroy parts of the evidence, the time to act is now.

He said ... "We're not gonna do it recklessly, to use Chief Redfearn's word. We're also not gonna hesitate. We recognize the clock's ticking. None of us are gonna be here forever. We wanna see this case solved for everyone involved and everyone impacted by it."

We reported earlier ... JonBenét's brother Burke Ramsey stressed in an interview with the Daily Mail last week that DNA recovered from underneath JonBenét's fingernail holds the key to solving her murder.

Burke -- who was 9 at the time of JonBenét's death -- said ... "We need to find that match. It's the best evidence we have."

In the end, Burke feels it's not just about closure but also clearing his own name, saying ... "I didn't do it."