He left home and became a cowboy on a large ranch on the Cherokee reservation. He hung around with some other adolescents who were always getting in trouble for juvenile offenses. One time he was arrested and charged with theft, but was later set free. In 1892, masked men robbed the express office at Nowata. As they rode from the scene, the horse threw one of the men. The horse ran away. It was later found on the property where Starr was a cowboy.
When he later rode into town on the horse, someone recognized the saddle. Starr was immediately arrested, but subsequently freed. He was so humiliated by the experience because his parents had taught him that being in jail was disgraceful. From that day forward he felt that if he could be treated like a criminal for not doing anything, he might as well act out the part.
Shortly afterward he joined a gang. In August 1892, the gang robbed a Missouri, Kansas and Texas train at Pryor Creek, Indian Territory. This fortuitous event introduced Starr to his bride-to-be. While guarding the train from outside a young woman jumped off the train and ran away. After the bandits rode away from the train they caught up with her. Starr gave Mary Morrison a ride to the nearest train station and sent her to her parents home in Joplin, Missouri. He later visited her there using an assumed name.
From then on began a spree of robberies all over Indian territory. In January 1893 Starr and his friends robbed two general stores and the depot at Choteau. A few days later they robbed the general store and the depot at Inola. In March 25, 1893, they robbed their first bank at Caney, Kansas, for $4,900. That job attracted lots lesser criminals and soon he had a full-fledged gang. They robbed another bank in Tron, Kansas. On May 5, they returned to Pryor Creek and robbed the Katy train for $6,000. On June 6, they robbed a bank in Bentonville, Arkansas, for $11,000.
