One of the most famous cases of Colorado occurred in September 1879. Tom Johnson and J. F. Seminole killed R. B. Hayward. They had hired him to guide them to a cattle outfit. Afterward, they returned to Denver and rented a horse and buggy, which they never returned to the stable. Cook and his assistant Carr tracked the man to Wyoming to Laramie, then Cheyenne and Sherman. A distinguishing characteristic was the two buffalo robes they stole from ranchers that they used in place of saddles. The one man also had a distinguishing white bone handled knife.
Sentinel was a half breed Sioux from the Pine Ridge Agency in the Dakota Territory. Cook caught up with him there. Unfortunately, while returning to Denver on the train the Indian jumped off the speeding train. A posse recaptured the prisoner and brought him to Denver. Cook put Seminole into a lineup with other prisoners and Mrs. Hayward identified him as one of the men who hired her husband. The stable man identified him too. When Seminole asked to see a lawyer Cook sent in a man who was actually one of his detectives. In this way they discovered the identity of other man, Sam Woodruff. Cook caught him near Council Bluffs, Nebraska.
Another famous case took place in 1871 north of Denver. A sheep rancher named S. K. Wall was killed by George H. Wetherill and E. E. Wight. They killed Wall and stole his herd of 400 sheep and some personal possessions. Cook caught up to them when Wetherill attempted to cash a certificate of deposit made out to Wall. The clerk recognized that the signature of endorsement was not Wall's handwriting. The two fled to Nebraska where they thought they would be out of Cook's jurisdiction. Cook caught up to Wetherill in Julesburg, Colorado and Wight in Nebraska.
