No one snatched her. The ransom note was over-kill. Why would a kidnapper kill JonBenet and then leave evidence of his/her handwriting behind? Especially since he/she left not one other piece of evidence.
http://jonbenetramsey.pbworks.com/w/page/11682457/Comparison to Other Famous RN's
Similarities to Ramsey Case
Child Killed Despite Ransom Demand. These include Bobby Franks (age 14), Marian Parker (age 12), the Lindbergh baby (age 20 months), Susan Degnan (age 6), Peter Weinberger (age 33 days) and apparently Clark Handa (age 3).
No Effort to Collect Ransom Demanded. These include Peter Weinberger (though failure to collect ransom amount left as instructed may have been due to incompetence of kidnapper) and Clark Handa.
Ransom Note "Bogus." Several of these "kidnappings" entail ransom notes that were "bogus" in the sense that the note was written with the intent to throw off law enforcement or the "kidnapper" knew the victim already was dead and could not be returned alive even had a ransom been paid (which, in some cases, it was). These include Bobby Franks (ransom paid), Marian Parker (ransom paid), the Lindbergh baby (ransom paid), Susan Degnan (body discovered before ransom paid), Peter Weinberger (ransom payment attempted), Gail Jackson (no ransom paid) and Clark Handa (no effort to collect ransom).
Bobby Franks (1924)
Case Details. This is the infamous Leopold and Loeb case, involving a college student and law student who kidnapped and murdered Bobby Franks in the course of committing the "perfect crime." During the course of trying to pay the ransom amount, the boy's father learned his son had been found dead. See details at Court TV Crime Library.
Side-by-Side Comparison to Ramsey Note. A "side-by-side" comparison of the RN to the note used by Leopold and Loeb in the kidnapping and murder of 14-year old Bobby Franks is at Webbsleuths.
Marian Parker (1927)
Case Details. Marian, age 12, "was snatched in 1927 by someone who sent ransom notes to the family. But kidnapping wasn't the motive; the "kidnapper" collected a ransom and delivered the girl back to her family -- she had been killed and her body desecrated in a classic case of Lustmord or lust murder. See an excellent summary by Mark Gribben." Source: Laura James at Clews The Historic True Crime Blog.
Lindbergh Baby (1932)
Case Details. Despite the payment of a ransom, the body of 20-month old Charles A. Lindbergh Jr. was found dead 73 days later, apparently having been killed close to the time of the kidnapping. See details at Court TV Crime Library.
Contents of Note. "Dear Sir! Have 50,000$ redy 2500$ in 20$ bills 1 5000$ in 10$ bills and 10000$ in 5$ bills. After 2-4 days we will inform you were to deliver the Mony. We warn you for making anyding public or for the polise the child is in gut care. Indication for all letters are signature and 3 holes" (full note here (link provided by Internet poster Athena).
Side-by-Side Comparison to Ramsey Note. A link to a scan of the note used in the case of the kidnapping of the Lindbergh baby, along a detailed comparison of the details of that case with the JBR case is contained in a letter from New York lawyer Darnay Hoffman to Boulder DA Alex Hunter.
Susan Degnan (1946)
Case Details. "A killer left a ransom note when he took Suzanne Degnan, 6, from her home in the middle of the night on January 6, 1946. Her dismembered body was found the next day. A child molester named Richard Thomas confessed to the murder, though notorious killer William Heirens also confessed to the killing. In either event, it was clearly a sex murder and not a kidnapping, regardless of the note. See the Court TV Crime Library." Source: Laura James at Clews The Historic True Crime Blog.
Contents of Note. "Get $20,000 ready & waite (sic) for word. Do not notify FBI or police. Bills in $5's and $10's." On the backside was a warning: "Burn this for her safty (sic)" (Crime Library).
Peter Weinberger (1956)
Case Details. Weinberger, an infant 33 days old, was kidnapped from the patio of his home 10 minutes after his mother placed him in a carriage. Despite several abortive attempts to deliver the specified ransom amount, the baby was never returned, and the kidnapper later confessed he had abandoned the baby (later found dead) shortly after the kidnapping. (Newsday.com).
Contents of Note. "The ransom note was scrawled in green ink on a sheet torn from a student notebook. 'Attention,' it said. 'I'm sorry this had to happen, but I am in bad need of money, & couldn't get it any other way. Don't tell anyone or go to the police about this, because I am watching you closely. I am scared stiff, & will kill the baby at your first wrong move ... Your baby sitter.' It demanded $2,000 in small bills. The money was to be placed in a brown envelope and left near the Weinberger home, next to a signpost at Albemarle Road and Park Avenue, at 10 o'clock the next morning." Newsday.com (link provided by Internet poster Athena).
Gail Jackson (1978)
Case Details. After murdering prostitute Gail Jackson, William Hance sent 5 letters to the Chief of Police to avert suspicion from himself (opinion).
Contents of Notes. "The letters were signed "Forces of Evil," a fictitious group the appellant had created. The second of these letters received by the Chief of Police demanded either the apprehension of the Columbus strangler or a $10,000 ransom in return for the victim's safety. In addition, the appellant found an Army Cap with a different unit insignia than his unit and placed this near the crime scene, also in order to avert suspicion" opinion(link provided by Internet poster Athena). Donald Pugh has observed that this note used the line "We are an organization composed of seven members."
Clark Handa (1984)
Case Details. Handa, age 3, "was kidnapped from his own home in 1984. A ransom note was left behind. Clark has never been found, and no one ever tried to collect any ransom for his return." details.
Source: Laura James at Clews The Historic True Crime Blog.