Forensic familial search methods carry risk of certain false matches

August 14, 2013

Forensic DNA-based familial search methods may mistakenly identify individuals in a database as siblings or parents of an unknown perpetrator, when in fact they are distant relatives, according to research published August 14 in the open access journal PLOS ONE by Rori Rohlfs and colleagues from the University of California at Berkeley and New York University.

Familial searching is a new forensic technique to identify a perpetrator if a crime scene DNA sample has no matches in a DNA database. In such a situation, law enforcement can look for a partial match to a known person in the database—a "near miss"—in the hope that the closeness of the indicates that one of that person's relatives is the perpetrator. Familial searches can reliably distinguish first-degree relatives from unrelated individuals, but may misidentify as being immediate family, according to this new research. As a result, second cousins, half- siblings and other relatives may be identified as siblings. The results suggest a 3-18% chance that a first cousin of a known offender could be misidentified as a full-sibling using current techniques, and up to a 42% chance that a half-sibling could be misidentified as a full-sibling.

The authors conclude that there exist two unanticipated likely outcomes of familial search policies. The study explains these as, "Investigations may wrongly target the immediate families of known offenders, because officers mistakenly believe that their lead is a first-degree relative. Second, investigations may ultimately probe far more deeply than initially imagined, because once officers are convinced that the source cannot be found among first degree relatives, they will widen their net of investigation to include more distant relations. Both of these consequences exacerbate the numerous presented by familial searching."

Explore further: Potential for incorrect relationship identification in new forensic familial searching techniques

More information: Rohlfs RV, Murphy E, Song YS, Slatkin M (2013) The Influence of Relatives on the Efficiency and Error Rate of Familial Searching. PLOS ONE 8(8): e70495. DOI: 10.1371/journal.pone.0070495

Related Stories

Potential for incorrect relationship identification in new forensic familial searching techniques

February 9, 2012
New research suggests that unrelated individuals may be mistakenly identified as genetic family members due to inaccurate genetic assumptions. This is particularly relevant when considering familial searching: a new technique ...

No higher risk of acute leukaemia in close relatives

December 15, 2011
(Medical Xpress) -- Parents, siblings and children of patients with the most common form of acute leukemia do not run a higher risk of developing the disease as was once believed, according to a new study from the Swedish ...

Spread of DNA databases sparks ethical concerns

July 12, 2013
You can ditch your computer and leave your cellphone at home, but you can't escape your DNA. It belongs uniquely to you—and, increasingly, to the authorities.

Recommended for you

Scientists provide insight into genetic basis of neuropsychiatric disorders

July 21, 2017
A study by scientists at the Children's Medical Center Research Institute at UT Southwestern (CRI) is providing insight into the genetic basis of neuropsychiatric disorders. In this research, the first mouse model of a mutation ...

Scientists identify new way cells turn off genes

July 19, 2017
Cells have more than one trick up their sleeve for controlling certain genes that regulate fetal growth and development.

South Asian genomes could be boon for disease research, scientists say

July 18, 2017
The Indian subcontinent's massive population is nearing 1.5 billion according to recent accounts. But that population is far from monolithic; it's made up of nearly 5,000 well-defined sub-groups, making the region one of ...

Mutant yeast reveals details of the aberrant genomic machinery of children's high-grade gliomas

July 18, 2017
St. Jude Children's Research Hospital biologists have used engineered yeast cells to discover how a mutation that is frequently found in pediatric brain tumor high-grade glioma triggers a cascade of genomic malfunctions.

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Newly identified genetic marker may help detect high-risk flu patients

July 17, 2017
Researchers have discovered an inherited genetic variation that may help identify patients at elevated risk for severe, potentially fatal influenza infections. The scientists have also linked the gene variant to a mechanism ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.