JonBenét Ramsey’s Dad John Thinks He Knows Who Murdered Daughter (Exclusive)

Over the years, speculation has run rampant about who killed JonBenét Ramsey in 1996.

The list of possible suspects in one of the most sensational murder cases of all time — when the 6-year-old beauty pageant contestant was found dead in the basement of her family’s Boulder, Colorado, home on Christmas morning — is long.

The list includes everyone from her parents, John and Patsy Ramsey, to her then-9-year-old brother, Burke, to convicted pedophile Gary Oliva and former teacher John Mark Kerr, who confessed to killing her in 2006 but was never charged. in connection with her death.

But one potential suspect stands out, at least to her father: a masked intruder who snuck into the home of a 12-year-old girl in Boulder, Colo., nine months after JonBenét’s murder. The suspect raped the girl and then ran away when the child’s mother scared him away.

“To me, it could have easily been the same person,” Ramsey tells PEOPLE in an exclusive interview.

But John adds, “The police blew it off as, ‘No, it’s not the same.'”

John opens up exclusively to PEOPLE ahead of the upcoming Netflix docuseries Cold Case: Who Killed JonBenét Ramsey?, streaming on Monday 25 Nov.

The three-part series takes a fresh look at the murder case that began when John found his young daughter dead in a dusty basement room in their exclusive neighborhood.

John and his late wife, Patsy, also found inside their home a menacing handwritten ransom note, presumably left by the killer.

But the deceased girl’s parents were soon suspected of the sexual assault and murder of their daughter, who died of suffocation and a blow to the skull.

The three-part Netflix docu-series delves into what John sees as missteps by authorities as he investigates JonBenét’s murder amid an international media frenzy that only made matters worse.

He says he is speaking out in part to encourage someone to come forward with new information and to “put pressure” on police to use advances in DNA technology and genetic genealogy to finally catch JonBenet’s killer.

For more on John Ramsey’s fight to see JonBenét’s murder solved in his lifetime, subscribe to PEOPLE now or pick up the new issue of People, on newsstands next week.

Speaking to PEOPLE, John expressed his shock when he learned that the unidentified 12-year-old girl had allegedly been raped in the middle of the night two miles from where the Ramseys lived — and that she went to the same dance studio as JonBenét .

“I think the method of surgery was exactly the same,” he tells PEOPLE. “I think the killer was in the house when we got home, waiting until we fell asleep.”

In the case of the 12-year-old girl and her family, “they came home, set off the burglar alarm, and the killer was already in the house. A very similar method, and yet the police blew it off. It was the same investigator as our case,” says John.

“But even the father of the little girl said, ‘On a scale of one to 10, I rate the police a minus five.'” They just … just boneheaded ignorance, but yes, I think it was very possible the same person.

John, Patricia and Burke were never charged in connection with JonBenét’s murder. Patsy died in 2006.

The Netflix docu-series in three parts Cold Case: Who Killed JonBenét Ramsey? begins streams Monday, Nov. 25.