Editorial: Allow familial DNA, but use it carefully

Suppose a new technology came along that could catch violent criminals. Should we use it?
Should we use it even if it feels like a creepy small step toward the lifetime genetic surveillance of all Americans?
That’s the conundrum raised by a new technique called “familial DNA,” which makes it possible to track down a criminal through the similar DNA of his or her relatives. New software soon will allow any state to begin familial DNA searches at a very low cost.