Easton, however, suffered from advanced Parkinson's, had a solid alibi and lived 170 miles from the crime scene. Six months after his arrest, police agreed to test four additional DNA markers. Easton was cleared.
When an FBI official learned of the British case, he called the coincidental match "mind-blowing." The chance of such a match was 1 in 37 million in the general population. But the odds of finding a match in Britain's extensive DNA database were 1 in 57.
For The Record
Los Angeles Times Thursday, May 29, 2008 Home Edition Main News Part A Page 2 National Desk 2 inches; 82 words Type of Material: Correction
DNA evidence: A May 4 article in Section A about the statistical calculations involved in describing DNA evidence in a murder case contained an arithmetic error. It said that multiplying the probability of 1 in 1.1 million by 338,000 was the same as dividing 1.1 million by 338,000. Actually, it's the same as dividing 338,000 by 1.1 million. The answer, a 1 in 3 probability of a coincidental match between crime scene DNA and genetic profiles in a state database, was correct.
For The Record
Los Angeles Times Sunday, June 01, 2008 Home Edition Main News Part A Page 2 National Desk 2 inches; 80 words Type of Material: Correction
DNA evidence: A May 4 article in Section A about the statistical calculations involved in describing DNA evidence in a murder case contained an arithmetic error. It said that multiplying the probability of 1 in 1.1 million by 338,000 was the same as dividing 1.1 million by 338,000. Actually, it's the same as dividing 338,000 by 1.1 million. The answer, a 1-in-3 probability of a coincidental match between crime scene DNA and genetic profiles in a state database, was correct.
In Puckett's case, David Merin, a deputy San Francisco district attorney, argued that the statistical adjustment recommended by the scientific panels would be "confusing and misleading." Like prosecutors around the country, he relied on the FBI's guidance. He cited a paper by an FBI expert, Bruce Budowle, that said the database adjustment was "not intended to replace" the general-population statistic.
The author of the National Research Council recommendation that Budowle cited told The Times that Budowle was wrong: "The intent was to replace Random Match Probability," said David O. Siegmund, a professor of statistics at Stanford University.
Superior Court Judge Jerome Benson ruled in favor of Merin. In doing so, he followed a California appellate court ruling on the same issue. The jury would never hear the 1-in-3 statistic.
'Our day in court'
When the case went to trial in January, the passage of three decades since the killing presented problems for both the prosecution and the defense.
Merin had warned Sylvester's four younger siblings, who flew in from Maine and Arizona, that because the crime-scene DNA was so degraded, a conviction was not a certainty.
"We just felt we needed our day in court," said Donna Sylvester Gaylord, 56, who went to nursing school with Diana. "And my sister deserved to have the way she died acknowledged by the state of California."
The other physical evidence at the crime scene couldn't be linked to Puckett. None of the 26 sets of fingerprints in Sylvester's apartment matched his. So Merin, who was 36 and trying his first murder case, relied heavily on circumstantial evidence.
Puckett "happened to be in San Francisco in 1972," Merin told jurors in his opening argument. Merin could not place Puckett in Sylvester's neighborhood on the day of the slaying. But Puckett had applied for a job near the medical center where Sylvester worked.
