Capital punishment: Is it RIGHT or WRONG?

In my mind, lethal injection is a lesser punishment than say, life in prison. When a person is executed, a needle is put into their arm, and he or she goes to sleep. Physically, it's a fairly painless way to go and essentially, his or her sentence is cut short. Those who are executed will never again have to worry about fighting for survival, growing old, or not seeing life p beyond the outer walls.