this is 79-year-old matthew mason of white plains. he's missing. he drives a 2010 burgundy ford taurus with maryland plates. the sheriff's department says he has dementia and they are worried about his safety. >>> brazen burglars stealing guns from homes, stores and cars from regular owners and even police. months investigating the impact the stolen guns can have on our streets. we have the latest on how these missing pieces can be tied to later crimes. >> reporter: stolen guns are a big problem in our area. an increasing number that aren't found at all. first at 6:00, burglary crews smashing their way into gun stores across the country. these break ins are on the rise and the stolen guns are turning up on our street. we followed the crew from one crew robbing stores in virginia to a gun found at a murder scene in maryland. see what this store owner did that kept the crew out. >> i woupldn't want to live wit myself if this stuff got in the wrong hand. >> they protect our streets with badge and a gun and we found sometimes police lose those guns sto