Meet one of them, real-life tough guy Bass Reeves... He arrested over 3,000 outlaws in his time, and shot and killed at least 14. He was an escaped slave who fled into the Indian Territory (now mostly Oklahoma) and lived with the Creek, the Cherokee, and the Seminole Indians until the 13th Amendment made him a free man in 1865. Along the way, he became a fighting man, a crack shot with revolver and long gun. Look at those eyes. It's always in the eyes.
He was a lawman in the Indian Territory for 32 years, and developed a reputation as one of the best deputy marshals to ever work out of the Fort Smith Federal Court. (And that -- working alongside men like Bill Tilghman and Heck Thomas -- meant something.) He was a sharp dresser and a polite, courteous man. He became a skilled, relentless detective, and brought in some of the most dangerous criminals of the time. Had his hat shot off a time or two, but never personally took a bullet...
Interesting addendum: Bass Reeves arrested his own son for murder. When the young man was charged with killing his wife, Reeves insisted that he be the one to track him down and bring him in. Two weeks later, he showed up with the kid in leg irons, and young Reeves was tried and convicted.
Bass Reeves' son did some serious time in the Federal Penitentiary in Leavenworth, Kansas, got out eventually, and lived out the rest of his life a peaceful citizen.