‘Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof;’ Congress shall not, states may. DC is under the jurisdiction of Congress. The DC cops were prohibiting the free exercise of religion unconstitutionally!
If I were to decide that I wanted to practice my pagen fertility ritual on the alter of a catholic church in Washington DC, and the cops are called in to remove me (I was asked nicely to leave, but I refuse), is that a violation of my free exercise of religion?