"Long before it's in the papers"
January 18, 2011

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Hair color of unknown offenders no longer a secret, researchers say

Jan. 3, 2011
Courtesy of Springer Science & Business Media
and World Science staff

DNA left at a crime scene can now re­veal the hair col­or of an un­known per­pe­tra­tor to in­ves­ti­ga­tors, sci­en­tists are re­port­ing.

The de­vel­op­ment was an­nounced by a group of re­search­ers who last year an­nounced they had de­vised a tech­nique to es­ti­mate the age of crime sus­pects from DNA re­mains.

The new re­search “lays the sci­en­tif­ic ba­sis for the de­vel­op­ment of a DNA test for hair col­or pre­dic­tion,” said re­searcher Ate Kloost­er­man of the Neth­er­lands Fo­ren­sic In­sti­tute at The Hague, a mem­ber of the team. “A val­i­dated DNA test sys­tem for hair col­or shall be­come avail­a­ble for fo­ren­sic re­search in the not too dis­tant fu­ture.”

The find­ings show, the sci­en­tists said, that based on ge­net­ic in­forma­t­ion in­ves­ti­ga­tors can learn with more than 90 per­cent ac­cu­ra­cy wheth­er a per­son has red hair; with a si­m­i­larly high ac­cu­ra­cy wheth­er a per­son has black hair; and with a great­er than 80 per­cent ac­cu­ra­cy wheth­er the col­or is blond or brown. 

The tech­nique even al­lows for dis­ting­ui­sh­ing si­m­i­lar col­ors, for ex­am­ple, be­tween red and red­dish blond, or be­tween blond and dark blond, they added. The nec­es­sary DNA can be tak­en from blood, sperm, sa­li­va or oth­er bi­o­log­i­cal ma­te­ri­als rel­e­vant left at a crime scene.

“That we are now mak­ing it pos­si­ble to pre­dict dif­fer­ent hair col­ors from DNA rep­re­sents a ma­jor break­through be­cause, so far, only red hair col­or, which is rare, could be es­ti­mated from DNA,” said co-author Man­fred Kayser of Eras­mus MC Uni­vers­ity Med­i­cal Cen­ter Rot­ter­dam in the Neth­er­lands. 

The scientists have al­so pre­vi­ously pub­lished re­search on pre­dicting eye col­or.

The new study “made use of the DNA and hair col­or in­forma­t­ion of hun­dreds of Eu­ro­peans and in­ves­t­i­gated genes pre­vi­ously known to in­flu­ence the dif­fer­ences in hair col­or,” Kayser said. “We iden­ti­fied 13 ‘DNA mark­ers’ from 11 genes that are in­formative to pre­dict a per­son’s hair col­or.”

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DNA left at a crime scene can now reveal the hair color of an unknown perpetrator to investigators, scientists are reporting. The development was announced by a group of researchers who last year announced the development of a technique to estimate the age of crime suspects from DNA remains. The new research “lays the scientific basis for the development of a DNA test for hair color prediction,” said researcher Ate Kloosterman of the Netherlands Forensic Institute at The Hague, a member of the team. “A validated DNA test system for hair color shall become available for forensic research in the not too distant future.” The findings show, the scientists said, that based on genetic information investigators can learn with more than 90 percent accuracy whether a person has red hair; with a similarly high accuracy whether a person has black hair; and with a greater than 80 percent accuracy whether the color is blond or brown. The technique even allows differentiating similar colors, for example, between red and reddish blond, or between blond and dark blond, they added. The necessary DNA can be taken from blood, sperm, saliva or other biological materials relevant left at a crime scene. “That we are now making it possible to predict different hair colors from DNA represents a major breakthrough because, so far, only red hair color, which is rare, could be estimated from DNA,” said co-author Manfred Kayser of Erasmus MC University Medical Center Rotterdam in the Netherlands. The researchers have also previously published papers on predicting eye color. The new study “made use of the DNA and hair color information of hundreds of Europeans and investigated genes previously known to influence the differences in hair color,” Kayser said. “We identified 13 ‘DNA markers’ from 11 genes that are informative to predict a person’s hair color.”