You get a lethal injection - you fucking die. How much brutality when dealing with death-row inmates would be sufficient for your thirst for blood to be satisfied?
And don't be fooled. There may be swift "justice" and there may be fair justice, but they rarely overlap.
One of the executed took several minutes to die as he struggled at the end of the rope. It reminds me of the execution of the commander of Andersonville. He was given a short drop and took several minutes to die, As he struggled at the end of the rope, the soldiers taunted him by yelling remember Andersonville over and over.