No time right now. Catch him, get him to sing, use the info he provides in the field, let it be known that he’s the source to discredit him. If you want an Eichmann-style trial, keep him on the QT somewhere secure until the intel he provides is fully utilized, and then years later have your trial. Eichmann was finally tried in 1961 for what he was doing 20 years prior. Of course, he was in the wind after the fall of Berlin, but if they had caught him right during the war, his relevance to the war effort would have taken priority.
I kind of like that scenario. You could trot him out whenever you wanted to remind folks what animals they are...