If a Muslim male robs a store I expect the cops to look for a Muslim male. I do not, however, expect them to round up all Muslim males, "just to be sure".
This is America. If you don't like freedom...
Suppose he tells you that he did it because his religion told him to. Then you look in his religious texts and lo and behold, his religion DOES tell him to do that. Suppose several more Muslims do it and you find that the vast majority of their fellows agree that they had every right to do it, and they are donating money to help them do it, and they celebrate every time another Muslim does it. THEN do you start thinking maybe their religion is not compatible with your Constitution?