After the Civil War, controversial Ohio politician Clement Vallandigham [wiki] became a highly successful lawyer who rarely lost a case.
In 1871, he defended Thomas McGehan who was accused of shooting one Tom Myers during a barroom brawl. Vallandigham’s defense was that Myers had accidentally shot himself while drawing his pistol from a kneeling position.
To convince the jury, Vallandigham decided to demonstrate his theory. Unfortunately, he grabbed a loaded gun by mistake and ended up shooting himself!
By dying, Vallandigham succeeded in demonstrating the plausibility of the accidental shooting and got his client acquitted.