TV shows explore shocking new theories on JonBenet Ramsey case

America will never forget how 6-year-old beauty pageant queen JonBenet Ramsey was found dead in the basement of her Boulder, Colo., home on Dec. 26, 1996. While the blonde girl's mother Patsy first reported her kidnapped, JonBenet's wealthy father John Ramsey later discovered her body and police determined she'd suffered a blow to the head and had also been strangled with a garrote.

This fall, to mark the unsolved murder's twentieth anniversary, a slew of TV shows have presented their own investigations into the crime, including: "The Killing of JonBenet: The Truth Uncovered" on A&E, "Who Killed JonBenet?" from NBC's "Dateline," "JonBenet: An American Murder Mystery," from Investigation Discovery, and CBS' "The Case Of: JonBenet Ramsey." Dr. Phil McGraw also interviewed JonBenet's father and brother for a three-part series.

Here, FOX411 takes a look at some of the TV specials' new theories and revelations:

What did the 911 operator hear? Dispatcher Kimberly Archuleta, who received mother Patsy's frantic 911 call claiming JonBenet was kidnapped, gave her first TV interview to "Dateline." Archuleta remembered that the call was so peculiar that "there was something inside me that said, 'Something’s not right.'" After Patsy thought she had hung up the call, Archuleta could hear what she thought were three voices discussing the situation. Although the Ramseys told police son Burke was asleep in bed throughout their JonBenet ordeal, audio experts believe the third voice on the tape could be the boy.

The brother did it? On the just-aired CBS special, a panel of forensics experts came to the stunning conclusion that JonBenet's brother, Burke Ramsey, killed the little beauty pageant queen. Although Burke was just 9 at the time, investigator James Kolar theorized when JonBenet snagged a piece of pineapple from Burke's nighttime snack, "out of anger, he may have struck her with…[a] flashlight." The team said that Burke had previously hit his sister with a golf club. Also, retired FBI profiler Jim Clemente said Burke acted like an untruthful "smart Alec" during childhood interviews with a detective and psychologist. The boy raised eyebrows by making hammering motions when asked about JonBenet's death, and remarking dispassionately after losing his sister, "I'm just basically just going on with my life." Clemente's opinion is that Burke killed JonBenet and their parents staged the crime scene "to protect the child they had remaining." However, Burke, now 29, told Dr. Phil he didn't kill JonBenet — while creeping out viewers by smiling throughout the interview.

An intruder did it? A&E's documentary implied that an intruder was able to climb in through the Ramsey's open basement window, write a ransom note, and kill JonBenet. Boulder Detective Lou Smit (now deceased) famously illustrated this theory by climbing through the window himself on video. But CBS experts, doing their own test in a recreated version of the Ramsey house, concluded that climbing through the window would have disturbed cobwebs that were clearly seen on the original crime scene video. However, Bob Whitson, a retired Boulder detective, told "Dateline" that a "sexually sadistic person and psychopath" most likely killed Jon Benet.

DNA evidence exonerates parents? Patsy Ramsey (who died in 2006) and husband John always maintained they had nothing to do with JonBenet's death. According to the A&E show, DNA evidence from 2008 proved that the Ramseys couldn't have killed their daughter—a revelation that also caused Boulder authorities to publicly clear them and apologize. Results from a spot of blood found on JonBenét's underwear the night of the murder belonged to an unidentified male, show experts claimed. But famed forensics scientist Dr. Henry Lee came to a different conclusion on CBS' "The Case," saying a female garment worker likely left her DNA there after handling the panties in the manufacturing process. He also found no evidence of sexual assault. Although John Mark Karr confessed to killing JonBenet, he wasn't charged because his DNA didn't match.

Was the D.A. deceptive? It was revealed in 2013 that a Colorado grand jury had actually voted to indict JonBenet's parents in 1999; Boulder District Attorney Alex Hunter decided not to charge them. But "The Case" noted that Hunter had chosen his words carefully in a press conference to imply the grand jury had decided differently. Former Boulder police officer Gretchen Smith told CBS she felt that Hunter's office didn't want to solve the case because they "did not want to hear that an affluent member of the community was guilty of a crime like this." Off camera, Hunter told Jim Clemente he couldn't legally ever comment on grand jury proceedings.