Do you think Eric knows that once they have the trial, the killer can claim that his constitutional rights were violated because he could not possibly get a fair trial in New York City?
And, therefore, the case would be overturned and he could not be tried again.
Are we being set up to let this man go free?
Yes. Any and all testimony he gave cannot be used against him. Any and all evidence gathered as a result of that testimony must be thrown out. And since he committed no actual crime in the US, there is no Constitutional jurisdiction for trial here. Only Congress can establish trial jurisdiction for crimes committed outside the US, and in this case Congress has done that for military tribunal only. The only recourse I see here is to try him for treason. It is the only Constitutional way for him to be convicted in a US civilian court.