New Yorkers know the drill: On practically every other subway trip, you encounter an unhinged person ranting to himself or shouting at straphangers. You avoid eye contact and usually nothing happens, short of having to later explain to your child what could make a man so angry, as well as what certain nasty words mean. Midday Sunday, that routine morphed into absolute horror. A muttering, pacing man took out a gun and murdered 48-year-old Daniel Enriquez, who was headed from Brooklyn to Manhattan on the Q train to have brunch with friends. All lives are created equal, and all losses of life ar…
