I have said as much here on several occasions, when people have said "LEOs won't go along with this."
There are no cops in my family (and I'm 100% Irish - go figure!), but I have absolutely no doubt that many, if not most, LEOs will not hesitate for a nanosecond, to confiscate guns, to arrest law-abiding citizens who happen to own suddenly "illegal" guns, or to participate in SWAT style raids (as if the old "No knock" drug raids, many of which have resulted in the injury or death of innocents, aren't already evidence enough of this).