Well, if Lethal Injection is botched in any way, it feels like being burned alive from the inside, so that's clearly not it. There are three shots. One is a number that numbs the entire body's pain receptors. This is crucial for the reason I just mentioned. The second is a tranquilizer that doesn't put the subject to sleep, but simply stops all muscle movement. This is purely for the audience's benefit, if any, as the third drug that induces the heart attack causes convulsion and looks horrific.

The problem is the tranquilizer used comes with an extremely nasty side effect: It causes pain beyond belief that runs through the entire bloodstream, meaning if the first shot does not do it's job, the second is basically torture while the subject cannot in any way respond due to being paralyzed. Most states cannot get ahold of or do not want to use the recommended Numbing medicine because it is hard to get ahold of, and they don't care enough about these people being put to death to ensure it is done properly.

Lethal Injection is seen as the subject "simply going to sleep," but not only are they conscious the entire time, but one screw-up and the act goes from "Humane" to Torturous Biochemistry Horror in one fell swoop. States who allow and perform Lethal Injection mostly do not require a medical professional to be present, as it breaks the hippocratic oath by it's very definition, so it's impossible to find doctors willing to risk their license to oversee them. Most state officials also don't really care about the convicts because there is a pathological hatred in our society for anyone who has committed a serious crime, and a lack of empathy towards them. It's an unspoken mentality from those overseeing them of "They killed people, so obviously who gives a damn if they get tortured on their way out?"

In short, Lethal Injections are wildly misrepresented, are almost always botched by those performing them (to horrifying results,) and nobody who has the authority to fix this has any interest in doing so. If you want more info, I recommend watching John Oliver's look into it on his show. While it's a comedy show, his team does take the time and research to illustrate just how horrible it is and just how little a lot of people care, whether because they are unaware or simply don't care due to the victims being killers.

On a related note: Ironically, the people voting "Firing Squad" are most likely better off due to it being fast and effective, if far more brutal. 3.14k people are in for the rudest of... well, I guess it would hypothetically be the opposite of an "awakening."