The gunman is seen on surveillance video walking up to the patrol car and firing through the passenger side window before running away.
Joshua Powell, former second in command at the National Rifle Association, said the gun group caters "to the extreme fringe."
Gun safety advocates expressed concern about the new data, which coincides with reports of record sales from firearm retailers across the country.
“Modern-day musket my ass,” tweeted David Hogg.
"They took my AR," Mark McCloskey told a right-wing radio program.
Police reform seems likely to join gun control and immigration as issues where Americans overwhelmingly support changes, but Congress is unable or unwilling to do anything.
Virginia Gov. Ralph Northam fires back: "I suggest you stop taking hydroxychloroquine."
The Canadian prime minister said Monday that his government would soon move forward with legislation to ban assault-style weapons.
Hypocrisy, thy name is Ken Buck.
Four moderate Democrats joined Republicans in rejecting a proposal pushed by Gov. Ralph Northam to ban certain semiautomatic firearms.