Lethal Injections; Too cruel for criminals?

Some prisoners executed by lethal injection in the United States may die of suffocation while they are still conscious and in pain.

A study done by University of Miami researchers said that a study concluded the drugs do not work as intended. Is it cruel? Or should we even car? Maybe they made someone suffer? Shouldn't they?? "Lethal injection is the primary method of execution for 37 U.S. states and the federal government, though more than a dozen states have halted or suspended the procedure because of legal or ethical questions." I personally do not think I even care. If they are being sentenced to death, they obviously made someone else suffer, or did something horrible. Does this make me a horrible person for thinking this way? The potassium chloride injection used has a burning sensation throughout the body. The pancuronium injection suffocates the body....which makes the lungs become paralyzed. That was considered the only reliable fatal part of the deadly cocktail. So, should we have sorrow they are suffering?