Chicago police look at traffic fatality data to calculate where to deploy officers, Maloney said. He pointed out that while police did not set up any sobriety checkpoints in Jefferson Park during the period reviewed by the Tribune, they did conduct a different kind of DUI enforcement there — special mobile patrols in which officers look for suspected drunken drivers. But data show that the Jefferson Park district trailed in that type of enforcement as well, tied with the Foster and Rogers Park districts for the lowest number during that time, with three.