Members of New York State’s Commission on Forensic Sciences voted late yesterday to authorize law enforcement to investigate family members whose DNA is a “partial-match” with an individual whose DNA is in the state’s databank.

Under existing law, DNA evidence from a crime scene is compared against DNA samples in the state databank, which have been taken from individuals who have been convicted of certain crimes. When a DNA sample in the state databank is a precise match with crime scene DNA, the individual from whom that sample was taken is typically considered a suspect.

The rationale for the new policy is that the partial-match DNA may implicate a blood relative of someone in the state databank. But the science and potential for human error make it far from certain. The New York Civil Liberties Union charges that the proposed partial-match policy poses a direct and immediate threat to privacy and due process rights. New Yorkers must not be considered suspects in crimes just because they might share similar DNA to someone in the state databank.

“A policy that implicates New Yorkers in a criminal investigation solely because they are related to someone with DNA in the state’s databank is a miscarriage of justice,” said Donna Lieberman, the NYCLU’s executive director. “The Commission’s proposal gives a new and alarming meaning to the notion of guilt by association.”

The use of partial-match DNA samples to conduct what is called “familial searching” is a relatively novel, and controversial, practice. It has received significant criticism from the scientific community.

In a statement issued today by Professor Roger Koppl, director of the Institute for Forensic Science Administration at Fairleigh Dickinson University, and Professor Daniel Krane, professor of Biological Sciences at Wright State University, the two scientists said, “The partial-match policy approved by the New York State Commission on Forensic Sciences ignores best scientific practices and important recent contributions to the scientific literature on the topic.”

The NYCLU also questions the authority of the Forensics Commission to authorize such a practice absent a vote by the state legislature.

“The Commission’s approval of a ‘partial-match’ policy broadens significantly the nature and scope of law enforcement’s use of forensic DNA,” said Robert Perry, the NYCLU’s legislative director. “This policy appears to be beyond the Commission’s statutory authority.”

The Commission voted to adopt the partial match policy by a vote of seven to four, with one member not present.

With the approval of the policy, the Commission will now issue a regulation that proposes procedures and practices by which the policy will be implemented.