in this "america tonight" excomplusive. the police chief advise aring president obama takes us behind the scenes. . >> he is paid to sell guns, this protect. >> what was that hearing like? >> it was challenging. >> reporter: jim johnson takes on the national rifle association, but oversees the 18th largest police department in america. baltimore county in marylands. >> there's a picture of you in the president. issue. >> i had the opportunity to sit president. >> johnson was a key advisor with president obama during white house meetings, on how to tackle gun violence and change the laws. >> take me behind the scenes if you would a little bit. >> prior to the president's announcements, what involved did you have in other law enforcement officials. >> for years, we have been meeting with federal administration, looking at reasonable legislation that issue. >> i'm a hunter. i own several weapons, and i certainly am a champion and believe strongly in the second amendment. i think, as many do, that we can create reasonable legis