Key dates in the JonBenet Ramsey case:
Dec. 26: JonBenet Ramsey, 6, is found dead in the basement of her Boulder, Colo., home. Patsy Ramsey says she found a ransom note demanding $118,000 for her daughter.
Dec. 31: Ramsey family hires attorney, publicist and investigators.
Feb. 24: Ramsey spokesman says family members know they are "at the top of the list of possible suspects."
April 18: District Attorney Alex Hunter says Ramseys are under an "umbrella of suspicion."
April 30: Ramseys interviewed by police in first formal sessions.
May 14: Two detectives, including the first to arrive at the Ramsey home, are removed from the case.
Oct. 10: Police Chief Tom Koby admits mistakes made early in the case.
June 23-25: Ramseys are questioned by police, their first interviews in more than a year. JonBenet's brother Burke, 9 at the time of her death, is interviewed for six hours.
Sept. 15: Grand jury begins investigation.
Oct. 13: District attorney says no indictments will be issued, cites a lack of sufficient evidence.
Dec. 20: New District Attorney Mary Keenan (now Mary Lacy) takes over investigation and promises a fresh look.
March 31: A federal judge in Atlanta concludes that the weight of the evidence is more consistent with the intruder theory than with the theory that Patsy Ramsey killed JonBenet.
April 7: Lacy issues a statement agreeing with the judge.
June 4: The Ramseys' attorney says DNA found in JonBenet's underwear did not match any samples in an FBI database of convicted violent offenders.
June 24: Patsy Ramsey dies at 49 following a long battle with ovarian cancer.
Aug. 16: A suspect, teacher John Mark Karr, is arrested in Thailand and tells reporters he was "with JonBenet when she died," but that "her death was an accident."
Aug. 24: Karr arrives in Colorado, prosecutors acknowledge case still in "early stages."
Aug. 28: Prosecutors decide not to charge the schoolteacher in the slaying after his DNA fails to match genetic material on the girl's body.
Boulder Prosecutors abruptly dropped their case against John Mark Karr in the slaying of JonBenet Ramsey on Monday, saying DNA tests failed to put him at the crime scene despite his repeated insistence he killed the 6-year-old beauty queen.
The move came just a week and a half after the 41-year-old schoolteacher was arrested in Thailand and put on a plane to the U.S. in what was regarded as a remarkable break in the decade-old murder mystery that had cast suspicion on JonBenet's parents.
Karr, 41, will be held in custody by the Boulder County sheriff's office pending extradition to Sonoma County, Calif., to face child pornography charges dating to 2001.
Sheriff Joe Pelle said Karr will be held in the same jail cell where he's been since last week. He described Karr as "polite and cooperative."
District Attorney Mary Lacy vowed to keep pursuing leads in JonBenet's death.
"This case is not closed," she said.
Karr emerged as a suspect in April after he spent several years exchanging e-mails with a Colorado professor in which he admitted responsibility for the slaying and provided grisly details, Lacy said.
According to court papers, Karr told the professor he accidentally killed JonBenet during sex and that he tasted her blood after he injured her vaginally. But officials at the Denver crime lab conducted DNA tests last Friday and failed to connect Karr to the crime.
"This information is critical because ... if Mr. Karr's account of his sexual involvement with the victim were accurate, it would have been highly likely that his saliva would have been mixed with the blood in the underwear," Lacy said in court papers.
Authorities also found no evidence Karr was in Boulder at the time of the slaying, prosecutors said.
Defense attorney Seth Temin expressed outrage that Karr was even arrested.
"We're deeply distressed by the fact that they took this man and dragged him here from Bangkok, Thailand, with no forensic evidence confirming the allegations against him and no independent factors leading to a presumption he did anything wrong," Temin said.
Prosecutors said they detained Karr after he began to describe an interest in several girls in Thailand "in much the same terms that he had described his interest in JonBenet," Lacy wrote.
Authorities were able to confirm that he "was having personal involvement with at least one of the girls" Lacy said. He was arrested a short time later.
Ramsey family attorney Lin Wood had no immediate comment. His clients, John and Patsy Ramsey, had known as recently as May that authorities were focusing their attention on Karr because of his e-mails with professor Michael Tracey. Patsy Ramsey died of cancer in June.
JonBenet Ramsey's aunt, Pamela Paugh, said she was disappointed there won't be a prosecution of someone in the case, but she is glad that justice has been done.
"I think our justice system worked as it was supposed to," said Paugh, who is Patsy Ramsey's sister. "We asked the DA to do her thing. She did it."
Paugh added: "My disappointment came about the end of December 1996 when we didn't have the killer then. We've had 9 1/2 years of disappointment and waiting."
Karr's arrest in Thailand was seen a break in the murder mystery that had cast suspicion over JonBenet's parents and led to myriad theories about the killer. But inconsistencies in Karr's account immediately raised suspicions that he might be an obsessed follower of the case who confessed to a crime he didn't commit.
Among other things, Karr's relatives insisted that he was with them, celebrating Christmas in Georgia and Alabama, around the time the child beauty queen was found strangled and beaten at her Boulder home on Dec. 26, 1996. They said that if Karr had not been with his family at Christmas, they would have certainly remembered it.
In an interview with the media in Thailand, Karr said he was with JonBenet when she died and that her death was an accident. Asked if he was innocent, he said no.
In an interview Monday with MSNBC, Gary Harris, who had been spokesman for the Karr family, said he knew the DNA wouldn't match.
Karr has been "obsessed with this case for a long time. He may have some personality problems, but he's not a killer," Harris said. "He obsesses. He wanted to be a rock star one time. ... He's a dreamer. He's the kind of guy who wants to be famous."
Karr was arrested in Petaluma, Calif., in 2001 and pleaded not guilty to five misdemeanor counts of possession of child pornography. He fled before he could be tried and still faces an outstanding warrant there. The Sonoma County DA's office did not return calls seeking comment.
Scott Robinson, a Denver attorney who has followed the case from the beginning, said prosecutors may now be back at square one in the JonBenet case.
"At this point, if they really do get a good lead on the case then it may be very difficult to convict," Robinson said. "It was never going to be easy without a confession and DNA confirmation."
As for Lacy's decision to bring Karr back from Asia, Robinson said she had no choice but to pursue the lead. He said Karr may be charged with lying about his role in the case.
"Seems to me there should be some criminal consequences," he said. "He has cost the taxpayers an enormous amount of money."
Associated Press writers Chase Squires in Boulder, Sandy Shore in Denver, Harry R. Weber in Atlanta and Scott Lindlaw in San Francisco contributed to this report.