I attended a gun show a couple of weeks ago. My buddy was looking for a new skinning knife for deer season. The knife tables were at the end of a row with a four foot aisle between them and a gun table. I walked to the gun table and saw a young lady looking at a shotgun on the corner of the table. We looked at each other and I asked her if she was going to buy the shotgun. She smiled and said no. As she walked away, I looked at the shotgun. It was on the corner of the table. There was a man and woman running the gun table. I then went back to where my buddy was haggling over a knife. My buddy told the dealer he would think about the deal and we walked around the show for a little while and returned to the knife table for another round of haggling. I began walking along the knife tables toward the gun table with the shotgun. A woman ran past me heading for the exit. I watched her running toward the exit and realized it was the woman from the gun table. As I turned back toward the gun table, I locked eyes with a man standing at the knife table. He was looking right at me and then looked way quickly. I then looked at the gun table and saw the shotgun was missing but the box was still on the table. I looked back at the man at the knife table and then looked down and saw him holding a long gun tight to his body partially covered by his coat. I looked back at him and he was looking at me. He then turned away from me and tried to cover the gun. I realized it was the shotgun I had looked at earlier. He must have taken the shotgun and then just turned in the aisle to make it look like he had been standing there the whole time. I walked past him to the man at the gun table. I told the dealer at the table what I saw and he followed me back to the man. The gun dealer saw the shotgun and grabbed the thief. Security held him until the police arrived. He was arrested. I wrote out a statement and it looks like I will be called as a witness if the case goes forward. I was glad I could help that dealer.