A powerful forensic search tool known as familial DNA is gaining clout for its ability to identify suspects when all else fails.
Recently adopted in the state of Virginia and under consideration in Pennsylvania, the controversial search technology is used in Colorado and California, where it was credited with nabbing suspects in serial murders.
In familial DNA searches, authorities collect crime scene DNA and search for a near — but not perfect — match with existing DNA in the criminal database, presumably from an incarcerated blood relative of the yet unknown suspect.
A near match may cause authorities to focus on a potential suspect, possibly the first break in a protracted investigation that otherwise has no leads.
“It will give critical investigative leads in the most serious cases that are not otherwise going anywhere,” said Carll Ladd, supervisor of the DNA division of the Connecticut state forensic lab.
Advocates tout familial DNA as the next practical step in maximizing the use of DNA, in a responsible manner, to solve crimes.
They say familial DNA searching should be used only when all other investigative tools have been exhausted and only in the most serious cases.
Even then, critics say, the search technique could infringe on privacy, unfairly target innocent people and disproportionately affect African Americans and Hispanics, the largest populations in the DNA database.
Some opponents also say the DNA database was created only to determine perfect matches among the 9.4 million offender profiles currently on record nationally or to link DNA in a series of crimes, not for partial identification.