SIOUX CITY, Ia -- The 1920s were a difficult time for American law enforcement, but they had an unusual tool in their arsenal to help them fight crime.
Sunday afternoon, former Sioux City Police Sergeant Dave Bishop showed the audience at the Betty Strong Encounter Center how postcards helped officers solve cases a century ago.
Dave Bishop, a Retired Sioux City Police Sergeant, told us, "The postcards are an interest of mine and that's how I wound up with this. It's just the story behind them and the use of them. These don't have pictures with them, so it's more of an imagination thing where you think: What happened? Where did the property go to? Did they ever solve these crimes?"
The cards in Bishop's collection came from police departments in Illinois, Iowa, Nebraska, South Dakota, Minnesota and Missouri.