(BOULDER, CO) — As the new Netflix docuseries “Cold Case: Who Killed JonBenet Ramsey?” reinvigorates public interest in the 1996 case, JonBenet Ramsey’s father said he’s more encouraged now than he’s been in a long time that the person who killed his 6-year-old daughter will be found.

“I’ve been trying for years to break the roadblock in the [Boulder, Colorado] police department, which has been there almost from day one. And we’ve made some, I think, significant progress,” John Ramsey told “Nightline” on Tuesday.

“They’ve done some changes internally. New police chief, they got rid of some of their not-performing detectives. And we have an open, pretty open communication line with the chief of police.”

“The media attention and pressure, I think, has shaken them up,” he added.

On the morning of Dec. 26, 1996, John and Patsy Ramsey woke up to find their daughter, beauty queen JonBenet, missing from their Boulder home and a handwritten ransom note left on the stairs. Hours later, John Ramsey discovered her dead in their basement.

JonBenet’s autopsy determined she was sexually assaulted and strangled, and her skull was fractured. Unknown DNA was found under her fingernails and in her underwear.

John Ramsey, Patsy Ramsey and their son were cleared as suspects in 2008.

Ramsey hopes new DNA technology using genealogy research could help police solve the case — and he wants the Boulder Police Department to share with him what they’re doing.

“When I talked to the chief of police a couple of months ago — maybe it’s been a little longer — he said, ‘Well, we don’t think DNA technology is there yet to do additional testing, and we’re doing some things, but I can’t tell you about it,'” Ramsey said.

“I firmly disagree with the fact that technology is not there yet. It is there. I’ve met with the founders of one of the premier labs. … They told me what they can do. They’d like to participate, they’d like to help.”

Joe Berlinger, who directed the new Netflix docuseries, told “Nightline” that the Ramseys were “brutalized by an unfair process that [police] largely contributed to — the idea that [the family members] were actually the killers. And in response to that, just good karma dictates that [the police] need to treat this family with the care that they deserve, and they should accept all outside help.”

The Boulder Police Department released in a statement about the JonBenet Ramsey case last week.

“We are committed to following up on every lead and we are continuing to work with DNA experts and our law enforcement partners around the country until this tragic case is solved,” it said. “This investigation will always be a priority for the Boulder Police Department. The assertion that there is viable evidence and leads we are not pursuing — to include DNA testing — is completely false.”

The department suggested that anyone with any information to contact detectives at BouldersMostWanted@bouldercolorado.gov or by calling its tipline at 303-441-1974.

Sources told ABC News this week that progress is being made in the investigation.

In the last years, a multi-disciplinary team of experts has been assembled to go through the remaining evidence and apply the most modern scientific and cold case techniques to try to solve the crime, sources said. The team has consulted with top experts in their fields, according to the sources.

According to a law enforcement official briefed on the case, tips have come in as recently as the last month and are being followed up on. The renewed investigative efforts of the Boulder police and partner agencies also stand in contrast to years of limited detective work to get to the bottom of the case.

John Ramsey is following up on leads himself.

He noted that he received a letter this week from a woman who wrote, “I think my husband is a killer” and asked him to call her.

“I will call her,” Ramsey said. “That isn’t the first time we’ve gotten that kind of lead. We always follow up.”

“I’m always looking for that silver bullet — that somebody knows something that wasn’t in the media,” he said.

Since the Netflix docuseries premiered on Nov. 25, Berlinger said he’s been getting tips as well.

Ramsey was interviewed for the docuseries, but noted that he hasn’t watched it because of the emotion the case stirs up.

“I’d like to watch it someday. But for now, it’s just difficult to go back and relive the history,” he said.

He expressed confidence that the case was presented accurately.

“Years ago, I said, ‘Why doesn’t God reveal the killer?’ Somebody said, ‘Well, maybe you’re not ready for that yet. And I thought, well, that may be right. Because initially you put me in the room with this creature, we won’t need a trial. The rage was so intense and I would have had no remorse,” Ramsey told “Nightline.”

“But obviously, that’s not the right thing to do. But that’s how I felt. Now, I want this chapter closed for my family benefit. And I think we’re making good progress in terms of publicly questioning what’s going on. … With pressure, they’ll pay close attention to it, I’m hoping.”

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