John Edgar Trainer served as a deputy under two legendary Bexar County sheriffs: T.P. McCall and John W. Tobin.
He was born on October 4, 1854 in Bexar County to David State Trainer and Rebecca Martin.
On October 5, 1876, he married Irene Amanda Martin, daughter of Thomas Martin and Jane Pooley. Bexar County records indicate Thomas gave his consent for the marriage.
In 1898, John was elected Bexar County Commissioner for Precinct #4.
After his term as County Commissioner, he served as a deputy under both Sheriff T.P. McCall and Sheriff John W. Tobin.
In 1908, he ran for the position of Constable for Precinct #1 for Bexar County. He won the election, and served as Constable for Precinct #1 until his death.
John died January 25, 1924. He is buried in the Confederate Cemetery in San Antonio.