He was a member of Butch Cassidy's Wild Bunch gang, operating out of the Hole-in-the-Wall Pass in Johnson County, Wyoming.
In August, 1896, Matt Warner killed two prospectors named Dick Staunton and Dave Milton, during a shootout near Vernal.
Warner, Coleman, and hired gunman Bill Wall were arrested, and eventually transported to Ogden, Utah, where they were held in jail.
In April 1897, the two women were sent home, while Cassidy and Lay began planning the robbery of a payroll shipment in Castle Gate, Utah.
On April 21, 1897, the payroll arrived, and Cassidy and his gang members simply walked out in broad daylight and took $7,000 at gunpoint.
A gang member named Joe Walker is alleged to have disabled the telegraph lines to prevent word of the robbery being put out to nearby law enforcement.
Kid Curry, who was by this time a member of the gang, killed Converse County Sheriff Josiah Hazen[2] during that pursuit.
Cassidy, Lay, Kid Curry, and other gang members Sam Ketchum and Bill Carver headed to New Mexico.
The robbery was successful, but a well-led posse under the direction of Huerfano County (Colorado) Sheriff Ed Farr soon cornered them near an area known as Turkey Creek.
In the first gun battle that followed, Doña Ana County Deputy Kent Kearney[3] was shot, dying the next day.
Lay was able to convince the prisoners to release the women, and for this act he was pardoned by Governor Miguel Antonio Otero on January 10, 1906.
They moved to Southern California, where Lay supervised the building of the All American Canal system in Riverside and Imperial Valley just north of the border with Mexico.
The loss of Lay deeply affected Cassidy, who for a time made attempts at getting amnesty from the Governor of Utah.
Josie Bassett on separate occasions told her cousin, her neighbor, and local historians she had been visited by Butch Cassidy and Elza Lay "in 1930 in Baggs, Wyoming".
Ben Kilpatrick and Laura Bullion were captured in St. Louis, Missouri, and George "Flat Nosed" Curry was killed by lawmen in Utah.