DNA evidence failed to link the notorious duo profiled in Truman Capote's novel, "In Cold Blood," to the 1959 slayings of a Florida family, ending authorities' best hope for closing the cold case.
Perry Smith and Richard Hickock had long been suspected in the December 1959 murders of Cliff and Christine Walker and their two children in Osprey, Fla. The family was slain one month after the pair killed the Clutter family in Kansas, a crime for which they were later hanged.
Authorities hoped DNA evidence could help them definitively link the men to the Walker family murders, and so in December 2012, the bodies of Smith and Hickock were exhumed, nearly 48 years after they were executed.
On Tuesday, the Sarasota County Sheriff's Office announced a DNA match was unable to be made. Only partial profiles were able to be taken from the exhumed bodies, Wendy Rose, spokeswoman for the Sarasota County Sheriff's Office, said in a statement.
Those profiles were not able to be matched to a DNA profile of a suspect authorities had developed from semen found in Christine Walker's underwear, Rose said.
Despite the fact that a DNA link was not able to be made, Rose said that "based on the totality of the evidence, investigators still regard Smith and Hickock as the most viable suspects in the Walker murders."
Walker Murders Stunned Quiet Community
After committing the "In Cold Blood" murders of Herbert Clutter, his wife and two children on Nov. 15, 1959, Smith and Hickock hit the road, hiding out from law enforcement in Mexico and Florida, among other places, according to Capote's book and law enforcement accounts. They were ultimately captured in Las Vegas.
But it just so happened that Smith and Hickock were near Osprey, Fla., on Dec. 19, 1959, when the Walker family was killed in their home.
The men were briefly investigated in 1960, but were ruled out as suspects after passing lie detector tests.
Det. Kim McGath, who has been assigned to the Walker case for the past four years, told ABCNews.com last year that she decided to start from the beginning in investigating the case, and through her research developed a hunch that Smith and Hickock could be responsible.
"Some things started jumping out at me," she said.
By the time the men reached Florida, they were spotted throughout the state looking for odd jobs to make a quick buck, often at mechanics' shops and gas stations, according to Capote's book.
It's possible the young family, who had been in the market to purchase a Chevrolet Bel Air, may have crossed paths with Smith and Hickock, who were driving a 1956 model and likely needed money, McGath said.
They were spotted several times in the Sarasota area the day of the murders, and after the Walker family was killed, one of the men was seen with a "scratched-up face," McGath said.
According to Capote's book, Smith recalled reading about the murders in the Miami Herald.
"Know what I wouldn't be surprised [about]? If this wasn't done by a lunatic. Some nut that read about what happened out in Kansas," Smith told Hickock while the two were on the beach in Acapulco, in an exchange Capote recounted in his book.
The men never confessed to the murders, and now with DNA evidence failing to link them, authorities may never know for certain.