He soon formed his own gang and began committing bank and train robberies throughout Kansas, Missouri, and Iowa, eventually earning a reputation as the premier bandit in the Midwest by the early days of Prohibition.

In 1920, through Callahan, Adams formed a partnership with outlaw brothers Ray and Walter Majors, and, on September 5, attempted a daylight robbery against a notorious Kansas City gambling den on Grand Avenue owned by Harry Trusdell.

However, a shootout between the bandits and tough employees of the illegal casino resulted in the death of gambler and gunman Frank Gardner and the eventual capture of the gang by police.

A third Majors brother involved in the botched robbery attempt, Dudley, escaped from the scene, only to be later arrested and serve time in Delaware.

With the exception of Brown (who was recaptured days later), the fugitives eluded capture from state authorities and eventually formed what became the newest incarnation of the Adams gang.

Having spotted the gang's vehicle, suspicious farmer Charles William Jones (1870–1921) contacted Murray Sheriff Ed West, and a group was formed to investigate and intervene.

Jones, having heard the gun battle from his farm up the road, grabbed his shotgun and ran to aid sheriff West and his group.

The gang, who had by now fled from the original site, drove up the road and exchanged fire with Jones, which left him mortally wounded.

The gang then committed their most successful robbery with the theft of $35,000 after robbing a Santa Fe express train near Ottawa, Kansas.

Later that night, the trio ran out of gas and stopped at a farm, where Adams attempted to steal a vehicle from farmer George Oldham.

Adams hid out until the funeral of fallen officer Fitzpatrick on November 22, at which he assumed the bulk of the police force would be present.

Eddie Adams' body was publicly displayed in the City Undertaking Parlor in a grisly celebration of the end of a reign of terror.