Let me try to re-frame my argument here as it seems Im not clear: McCroskey, absent a forensics miracle, does not have a not guilty plea available to him. Or rather, he does, but it will fail and he will be put to death.
He does, however, have the ability to make the argument that hes not guilty by reason of insanity. Regardless of whether this will work, this is significant for a few reasons.
Trials are conducted in a series of stages. Right now, they are in a pretrial stage. Before trial there will be a pretrial conference between the DA and the Defense where the DA is going to let the defense know whether or not, in the event of a guilty plea, they will pursue the death penalty. If they are, the Defense can then say they will pursue a not guilty by reason of insanity plea.
The NGI defense is significant in a few a ways. First of all, it will force the case to go to hearing on the merits to determine McCroskeys culpability. This will take a lot of time and a lot of money. Second of all, the prosecution could theoretically lose, as no one knows McCroskeys sanity.
This is an important bargaining chip in saving his life. The DA could decide that they dont want to take it to trial and offer McCroskey a plea bargain of life without parole. Or, they could still take on the case, forcing the aforementioned hearing.
I believe that there is a misconception that in the event that the NGI plea fails the Jury will stand up and say, like they do on Law and Order, We the jury find that McCroskey is guilty and should be sentenced to death.
Thats not how it works.
After the verdict comes in, the case moves into the sentencing stage, where the prosecution and defense will essentially argue whether McCroskey deserves to be put to death. You can imagine the prosecutions argument. The defense will probably put McCroskeys mother, sister, perhaps father, and friends on the stand to advocate for their son. They will also have their insanity defense available: that McCroskey should not be put to death based on the psychological analysis originally proffered in the trial. Psychiatrist and other testimony. This is how arguing McCroskeys insanity could help save his life.
Both phases, the criminal aspect and the sentencing, could be before juries. Or, McCroskey can waive his right to a jury trial and simply have a bench trial (where the judge decides) .
