'American Sniper' Murderer claims he was insane. Was he?

Chris Kyle 'American Sniper' - Played by Bradley Cooper

Chris Kyle and a friend were gunned down at a Texas shooting range. Now, the accused murderer Eddie Ray Routh claims he was insane at the time of the shooting.  Was he?

THE INSANITY DEFENSE:

If a defendant can show that he was insane at the time of the crime, he will be acquitted by "not guilty by reason of insanity." The reasoning behind allowing this "exception" to the law rests in the purposes of punishment: deterrence and retribution - If punishing someone will not deter that person from doing it again, and that person could not help doing what he did, what is the purpose of the punishment?

     How to prove insanity?

In Texas, (where the murder is being tried) the defendant must suffice either the 1) M'Naghten (Right-Wrong) rule, or  2) the Irresistible Impulse rule. Routh is attempting to convince the jury that he is insane under the first rule, the M'Naghten "Right-Wrong" Rule. 

For Routh to suffice the M'Naghten "Right-Wrong" Rule, he must prove two things: 1. That he had a mental defect or disease; and 2. As a result of that mental defect, he did not understand the "nature and quality" of his actions, or he did not know his actions were wrong. 

So far, it has been quite clear that Routh has a mental defect, the prosecution has even conceded this. Routh had Post-Tramatic Stress Disorder (PTSD) at the time he pulled the trigger. The real questions for the jury are "Did Routh understand the nature and quality of his actions?" and "Did he know his actions were wrong?"  Did He?

SO IS ROUTH INSANE?

The last thing the Jury heard before deliberations was a quote by Routh about the murder. He said:

". . . I shot them because they wouldn't talk to me. . . I feel bad about it, but they wouldn't talk to me. Im sure they've forgiven me." 

The prosecution thinks this quote is imperative to finding him not insane because to "retaliate" suggests an understanding of the "nature and quality" of his actions - it will cause harm.    For example: Routh's feelings were hurt because he believed his victims were ignoring him. So, as a response, he retaliated. He shot them, intending to inflict the same pain that he felt upon them. He intended harm and understood that shooting them would harm them.

      But did he know that inflicting that pain was "wrong"?

REMEMBER, It is not enough that Routh knew his actions would cause pain, he must have also believed that his actions were "wrong." 

This is a guy who spent much of his influential years killing people as a soldier. He was trained to fire without hesitation and to not feel the consequences of killing. He was instructed that killing the enemy protects his country.   But  did this training remove all emotional understanding of killing? What about killing two of his own? Two of his "brothers"?  Did he really think that killing two fellow military men was morally acceptable?   -  To be found insane, he would have to. 

These are the questions the Jury will be losing sleep over. I invite your responses below. Weigh in and be heard.

Thanks for reading.