What Genetic Genealogy is Revealing about CODIS

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When CODIS was established in 1994, many did not predict the almost overwhelming role it would play in the criminal justice system. The ushering in of the DNA database was a revolution at the time, one that is still going on. In the 3+ years since the Golden State Killer’s arrest, there has been another DNA revolution—forensic genetic genealogy (FGG).

FGG is now to DNA identification what CODIS was in the 1990s, argues Colleen Fitzpatrick, president of Identifinders International LLC.

But, “to do FGG, you don’t really need to know anything about CODIS,” says Fitzpatrick.

While that is technically true, in her talk at ISHI 32, the FGG pioneer used a different lens to examine CODIS—one that explores what her field has revealed about the DNA database and the criminal justice system as a whole.

Today, CODIS contains more than 20 million DNA profiles. Still, there are legal reasons why certain offenders are not in the database.

Take for instance Patrick Leon Nicholas, who was arrested for the 1991 murder of high school student Sarah Yarborough. Nicholas was known to the police as he has served time in prison for an attempted rape in 1983 (before CODIS). In 1993, he was arrested for child molestation of his stepdaughters. However, the mother of the girls refused to testify, allowing Nicholas to plead down to gross misdemeanor assault—avoiding CODIS yet again. His brother, Edward, was entered into CODIS for first degree rape, but Washington state doesn’t allow familial searching, so the connection was never made.

Fitzpatrick used FGG to identify Nicholas in 2017, but says if not for the CODIS loopholes, he probably would have been identified just a few years after he murdered Yarborough.

Building on that epiphany, as Fitzpatrick calls it, the FGG experts decided to launch an informal survey based on 100 cases solved with FGG. She sorted them into five categories:

  1. Suspects with no known criminal history
  2. Suspects who committed crimes that pre-date CODIS (Before 1995)
  3. Suspects with non-felony offenses, traffic tickets, etc.
  4. Suspects with felonies
  5. Suspects known to have slipped through the cracks

Upon analysis, a minimum of 37% of cases in the first two categories would only be solvable by FGG. For cases fitting the last three categories, Fitzpatrick says many could have been solved through expansion of DNA collection laws. Still, some of them would need FGG to create an investigative lead—proven through the fact that all of these cases were ultimately solved by FGG.

Some states have pledged to fill in CODIS gaps where they can, like Washington where Attorney General Bob Ferguson is leading a lawfully owed DNA project for sex offenders. In the meantime, FGG is an extremely effective way to support CODIS.

The technology has already shown it can identify offenders with no criminal past and those who committed crimes pre-CODIS. Additionally, it can help identify witnesses—who are not eligible for CODIS upload—from evidence left at crime scenes, possibly leading to more investigative leads. FGG can rule out candidates via target test and can provide exclusions though ethno-ancestry and phenotype, something Fitzpatrick believes was key in the arrest of the Golden State Killer.

“I believe, down the home stretch with the Golden State Killer, the fact that they knew he had blue eyes and could eliminate many of the other candidates [was crucial],” she said.

 

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