As the FBI faces pressure to expand its Combined DNA Index System (CODIS) to allow for “familial searches,” George Washington University law professor Jeffrey Rosen issues a cautionary plea. Familial searches, which follow up on near-DNA matches in an effort to pinpoint a relative who may be responsible for a crime, have shown a 10 per cent success rate in the U.K. But Rosen argues that because of the racial disparity in the CODIS databank-African Americans represent 13 per cent of the U.S. population, but account 40 per cent of convicted offenders-black families might be four times as likely to be put under genetic surveillance as their white counterparts. At the same time, the controversial inclusion of arrestees in the DNA databank in several states could exacerbate the disparity further and, he predicts. “A national decision to begin familial searches without explicit congressional approval might cause a political firestorm that would imperil political support for the entire CODIS system,” says Rosen.