JonBenét Ramsey was only 6 years old when she was found dead in her family's home on Dec. 26, 1996. The child beauty pageant queen had been brutally murdered and was found in the basement of the Ramsey home in Boulder, Colorado. The search for Ramsey’s murderer has already spanned nearly two decades, but it has yet to yield results.

Several TV projects and documentaries devoted to the famous cold case are set to premiere this month, including NBC’s “Dateline: Who Killed JonBenét Ramsey,” CBS’ “The Case Of JonBenét Ramsey” and Lifetime’s “Who Killed JonBenét?Prior to the debut of these specials, here are facts you should know about Ramsey’s murder and its aftermath.

How did JonBenét die?

In the morning of Dec. 26, Patsy Ramsey, JonBenét’s mother, found a ransom note asking for $118,000 for the child. She then called 911, and a search was conducted for the missing girl. During an afternoon search of their Colorado home, JonBenét’s body was found by her father in the wine cellar, and she had been tied up and covered with a blanket. She sported various wounds on her face and back and had duct tape over her mouth and a garrote around her neck, according to Denver Post

According to the autopsy, JonBenét had been struck on the head with an unknown object with enough force to knock her unconscious, before being strangled to death. Though asphyxiation by strangulation was the official cause of her death, authorities believe that JonBenét would have eventually succumbed to her head injury.

Evidence of vaginal trauma was also found, but authorities said it was inconclusive. “The rest of the scene we believe was staged, including the vaginal trauma, to make it look like a kidnapping/assault gone bad,” former Boulder police chief Mark Beckner said in a Reddit AMA last year.

What was in the ransom note? 

Patsy Ramsey told authorities that she found out that JonBenét was missing after finding the ransom note, which was two-and-a-half pages long, on the staircase. The letter was addressed to JonBenét’s father and demanded that he withdraw $118,000, which was nearly the exact amount of the bonus John Ramsey had received earlier that year. In the letter obtained by CNN, he was also told to wait for additional instructions and was warned not to tell the authorities or anyone else of his daughter’s disappearance or JonBenét would be killed.

After further investigation, it was discovered that the paper used for the letter came from a writing pad in the Ramseys’ home. John Ramsey and other family members were cleared of suspicion after undergoing a handwriting test. Patsy Ramsey’s handwriting “set off alarm bells,” but analysts could not conclusively determine that she had written the letter. Analysts also noted that the letter was “unusual” compared to normal ransom notes since it was longer and the amount being demanded was too specific.

“The FBI told us they’d never seen a 2.5 page ransom note,” said Beckner last year (via Fox13). “No note has ever been written at the scene, and then left at the scene with the dead victim at the scene, other than this case.”

What happened during the investigation?

The Boulder Police Department had mostly focused on the Ramseys during the early stages of the investigation, which led to them facing a barrage of criticism for their handling of JonBenét’s case. It’s believed that they were too focused on proving that JonBenét’s family members were guilty of the murder that they failed to thoroughly investigate other important leads.

In addition, some major blunders made by the police during the initial investigation resulted to more than a few setbacks for the case. The crime scene wasn’t sealed off properly after authorities arrived at the Ramseys’ home, and unauthorized individuals were able to enter and leave the house before the initial investigation was complete, resulting to evidence being compromised, Fox2Now reported. In 2002, JonBenét’s case was turned over to the district attorney’s office because “the Ramsey family had no confidence in the police.”

Who were the suspects?

Over the past two decades since JonBenét’s death, more than 140 suspects have been investigated and questioned by police. Until 2008, police largely focused their efforts on the Ramsey family, including JonBenét’s older brother Burke, who had been 9 years old at the time of her death. In 1999, a grand jury voted to indict JonBenét’s parents John and Patsy for abuse, but the judge did not sign the indictment since there wasn’t conclusive evidence to prove it beyond doubt. The Ramseys were later cleared of all suspicion after it was discovered that the DNA found on the child beauty queen’s underwear and leggings did not match any of her family members.

The prime suspects in JonBenét’s murder also included Bill McReynolds, a local Santa Clause who had stopped by the Ramseys’ home two days before the 6-year-old’s death, according to CNN. Coincidentally, he also had a daughter who had been kidnapped 22 years before. Michael Helgoth was also investigated due to his suspicious behavior surrounding the murder. Both men were later cleared of all suspicion.

Has anyone confessed to the crime?

In 2006, a schoolteacher living in Thailand named John Mark Karr confessed to killing JonBenét, according to NBC. He was flown back to the U.S., where he claimed that her death had been an accident. He was cleared and released less than two weeks after his confession when it was discovered that his DNA did not match with what was found on the child’s clothing.

What are other theories that could help find JonBenét’s murderer?

Over the duration of the investigation, the intruder theory has been debated again and again. Some believed that an intruder could have entered the Ramsey home and killed JonBenét based on the evidence that a basement window had been broken and an unidentified footprint had been found at the crime scene. However, physical evidence such as undisturbed cobwebs seemed to suggest that those details were intentionally put there as part of a set-up, according to author A. James Kolar, who led the investigation of JonBenét’s murder for the Boulder District Attorney’s office from 2005 to 2006 (via Today). But when the case was reopened in 2009, authorities have begun treating the intruder idea as a possible option.