Following the tragic shooting in Aurora, Colorado, Moyers aggressively went after the National Rifle Association, calling the group "the enabler of death -- paranoid, delusional, and as venomous as a scorpion."
O'Reilly mocked Moyers for his criticism, saying the PBS host "has no clue, no clue at all."
"He apparently believes that federal and state governments can actually control gun crimes," O'Reilly said with disbelief. "That's so dumb it hurts."
O'Reilly listed off gun violence statistics in various cities, highlighting that Chicago has seen 1136 shootings this year, even with a ban on hand guns in public.
"How about your state, Bill, New York?" O'Reilly taunted. "It has the fourth toughest gun law in the country. Sounds good, doesn't it? Ready? 2011 - nearly 4000 guns confiscated by New York City cops."
O'Reilly continued to mock Moyers by calling him a genius and saying, "PBS [is] very lucky to have you."