You may not fear the NRA, but you should be absolutely terrified by fact-checkers.
Every state has certain standards for law enforcement training and certification. These include training in use of force and when the use of force is permitted. Instructors in all of these must be certified by the state.
In 2017, police shot and killed 19 unarmed blacks out of a total of 68 unarmed people. Police handled nearly 9.2 million criminal complaints, including nearly 1.25 million violent crimes.
Your attribution of unjustified police shootings to the NRA and NRA-certified instructors is patently ridiculous. There are more than 800,000 sworn law enforcement officers in the U.S. This includes state police, municipal police, county sheriffs, county constables, city marshals, game wardens and other wildlife and conservation officers and reserve officers in all 50 states and the District of Columbia. There are no statistics on how many of these officers were trained solely by NRA instructors but the evidence points to a darn good job being done by police instructors in general.