When police trace the ownership of a crime gun, they often hit a dead end when the owners of record say their guns were lost or stolen. Krasner and others say they’re just lying, and are often selling those guns to felons who use them in crimes. They say responsible gun owners do tell police when their weapons are lost or stolen. Philadelphia officials say more than half of the guns used in crimes are in the hands of someone other than the original buyer. The actual number isn’t known for sure because Philadelphia does not release its gun trace statistics to the public. Chicago, which does release gun trace data, reports that 95 percent of its crime guns are traced back to someone other than the original purchaser.