The Leica M rangefinder camera still sets the standard of acceptable shutter noise in many US courtrooms today. Here is a quote from Minnesota court’s General Rules of Practice document:
And another quote from Vermont court’s “tiquette for Media document:
Not more than one still photographer, utilizing not more than two still cameras with not more than two lenses for each camera and related equipment for print purposes shall be permitted in any court proceeding. Such cameras shall produce no greater sound than a 35mm Leica “M” Series rangefinder camera.
Similar rules exists also in other states.