(RNS) A First Amendment watchdog group is suing a Texas sheriff for placing Christian cross decals on several county patrol vehicles.

Two atheist members of the Freedom From Religion Foundation filed the lawsuit Monday against Brewster County Sheriff Ronny Dodson in federal court in the Western District of Texas.

“Whether it is a cross, a star and crescent, or a pentagram, law enforcement must remain neutral on matters of religion in order to foster public confidence in their impartiality,” said Annie Laurie Gaylor of the FFRF, a group that sees its mission as defending the separation of church and state.

The Brewster County Sheriff’s Office posted a commentary on its Facebook page which stated that Dodson provided the decals because he “wanted God’s protection over his deputies.”

The FFRF argues this violates the establishment clause of the Constitution and has asked that the court declare that religious messages not be placed on Brewster County property.

In 2015, the FFRF lodged a complaint when a Georgia police officer placed a decal reading “In God We Trust” on his patrol car, calling it “inappropriate” and offensive. The group contacted more than 50 law enforcement agencies across the country with similar complaints last year.

(Aysha Khan reports for RNS)