 But here's the thing. Getting answers about where crime guns come from wasn't always a secret. Trace information, data that shows where a gun came from, used to be public, available on a $20 CD-ROM back in the 90s. And that included thousands of police weapons that had been sold off and showed back up at crime scenes. And it was happening all over the place. Gang murders in New York. A homicide in St. Louis. A white supremacist used one to fire on a daycare center.