DNA matches aren't always a lock
By Jason Felch and Maura Dolan,
Los Angeles Times
| 05. 03. 2008
Police found the naked body of Diana Sylvester near her Christmas tree.
The 22-year-old San Francisco nurse had been sexually assaulted and stabbed in the heart. She lay on her back, her neck laced with scratches and her mouth open as if frozen in a scream.
For more than three decades, Sylvester's slaying went unsolved. Then, in 2004, a search of California's DNA database of criminal offenders yielded an apparent breakthrough: Badly deteriorated DNA from the assailant's sperm was linked to John Puckett, an obese, wheelchair-bound 70-year-old with a history of rape.
The DNA "match" was based on fewer than half of the genetic markers typically used to connect someone to a crime, and there was no other physical evidence.
Puckett insisted he was innocent, saying that although DNA at the crime scene happened to match his, it belonged to someone else.
At Puckett's trial earlier this year, the prosecutor told the jury that the chance of such a coincidence was 1 in 1.1 million.
Jurors were not told, however, the statistic that leading scientists consider the most significant: the...
Related Articles
By Yelena Biberman and Jonathan D. Moreno, Bioethics Forum | 04.16.2024
A quiet biological revolution in warfare is underway. The genome is emerging as a new domain of conflict. The level of destruction that only nuclear weapons could previously achieve is fast becoming as accessible as a cyberattack.
Now for the...
By Jorge Barrera and Rachel Houlihan, CBC | 04.09.2024
A Canadian DNA laboratory knowingly delivered prenatal paternity test results that routinely identified the wrong biological fathers — ruling out the real dads — and left a trail of shattered lives around the globe, a CBC News investigation has found...
By Timnit Gebru and Émile P. Torres, First Monday | 04.14.2024
The stated goal of many organizations in the field of artificial intelligence (AI) is to develop artificial general intelligence (AGI), an imagined system with more intelligence than anything we have ever seen. Without seriously questioning whether such a system can...
By Carey Gillan, UnSpun | 03.18.2024
A Mexican standoff with the United States turned into a Mexican smack-down this month with the release of Mexico’s formal rebuttal to US efforts to overturn limits Mexico has ordered on the use of genetically modified (GM) corn and the...