They tweeted: “A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.”
The attack on a Kings Sooper grocery store in Boulder is reported to have taken place on Monday at 2:50pm local time (8:50pm GMT).
Of the 10 killed in the shooting, one was confirmed as being a Boulder police officer. A suspect is now in custody.
Just after 6am MST on Tuesday (12pm GMT), the NRA shared its quote from the second amendment, in a post which has been described as “insensitive” by users on Twitter:
Others commented on the wording of the amendment itself in light of yesterday’s tragic events:
The NRA is yet to respond to the criticism.