Well we might not like it, but he is right. In NYC, that was the case.
John Lott, and others that have studied the subject and written extensively on it, would beg to differ.
The crime rate in that God-forsaken hell-hole of a northeastern-corridor city, WOULD have gone down MUCH sooner and MUCH more dramatically if the liberal gun-grabbing dems and RINOs that run that Police State had enabled the law-abiding citizens to practice their God-given 2nd Amendment RIGHTS by using Concealed Carry.
Correlation does not equal causation.
Actually - it isn't the "gun control" that lowered crime in NYC - it was the more serious enforcement - going into neighborhoods that police had shunned before, actually arresting people instead of letting them slide, agressive prosecution, and yes, even some "profiling" based simply on appearance.