Oswald Cobblepot (Earth-1: Pre-Crisis)

"Gotham's used three ways to kill people on death row. Electric chair, firing squad, which made a brief comeback under Mayor Cobblepot, and the gas chamber."

- Luke Fox to Kate Kane

Oswald Cobblepot was the former Mayor of Gotham City and a patient at Arkham Asylum.

Mayor of Gotham City
At some point, Oswald Cobblepot was elected as the Mayor of Gotham City. During his tenure, firing squads became a method of execution for death row inmates.

Arkham Asylum Breakout
Following this, he was incarcerated in cell number 341 at Arkham Asylum. During the Arkham Asylum Breakout, Cobblepot escaped his cell after John Deegan opened all the cell doors, but he was soon returned by The Flash.