Unsolved: Evidence Doesn't Talk

Surveillance is life today. Doorbell cameras, convenience store security tape, traffic light cameras. We know we're tracked. We're used to it and frankly, we expect it.

Those cameras are supposed to make us feel safe and when unsafe things happen, that video can go viral. It can capture gas station robberies, gun store heists, car break-ins.

Surveillance video has become so normalized, do the most dangerous criminals even care about getting caught on camera?

When Donna Brown was murdered on the island city of Galveston, Texas, her alleged killer was seen on video walking away from the scene. However, despite the surveillance, the killer is still out there.

Studies show cameras help a little when it comes to solving property crimes, but they're almost no help solving violent crimes.

That's also the story of the Reyes family. The couple was shot to death as cameras caught the barrage of gunfire. Still, the video hasn't helped track down the killers.

If surveillance video is the best evidence in a cold case, is there hope it can get solved? Or will the cases go unsolved forever?