More than a dozen University of Kansas professors have issued a statement criticizing school officials for putting a colleague on leave after he posted a controversial tweet following the deadly Navy Yard shootings in Washington last week.

The Lawrence Journal-World reports 14 Anthropology Department professors and department chairwoman Jane Gibson signed the statement Friday in support of journalism professor David Guth.

Guth was widely criticized for posting a message on Twitter after the Sept. 16 shootings that said blood was on the hands of the National Rifle Association and added, “Next time, let it be YOUR sons and daughters.”

The professors’ statement says the university’s violated Guth’s right to free speech by placing him on indefinite leave, and that the action has a chilling effect on academic freedom.