Penrod and His Twin Brother (1938)

Penrod Schofield's mischievous dog Duke is falsely accused of biting Penrod's spoiled friend Rodney. The real culprit is Snook, a dog belonging to Danny, the new kid in town who coincidentally looks exactly like Penrod. Penrod and his gang of "junior G-men" want to hide Duke with a friend in a neighboring town, so they send Rodney on a wild-goose chase with a messenger pigeon to get him out of the way, but the police nab Duke before the gang can get him to the train station, but Duke escapes, and Rodney is captured by a real-life "most wanted" gang for witnessing a payroll robbery. When Penrod and his gang meet Danny, they realize why Duke was blamed for the dog bite. When they go to the police to explain, they learn of Rodney's predicament. They receive a clue from Rodney via messenger-pigeon but are unable to convince the police, so they (including Danny) search for Rodney themselves. Duke has managed to follow Rodney to the robbers' hideout and gives away their location. The "junior G-men" rescue Rodney and capture the crooks.