Embed from Getty Images

The Shreveport Police Department will no longer host or promote prayer vigils after the Freedom From Religion Foundation—a national nonprofit that advocates for the separation of church and state—argued that the practice was unconstitutional, according to the Shreveport Times .

In a letter to the department, the group argued that the department pose violated the United States Constitution because—they say—the department promotes or "prefers religion over nonreligion [sic]," which violates the Constitution's Establishment Clause.

This clause—in the First Amendment to the Constitution—prohibits the government from unduly preferring religion over non-religion, or non-religion over religion, according to Cornell Law School .

"As a police department, you serve a diverse population that consists not only of Christians, but also minority religious and nonreligious citizens," the Freedom From Religion Foundation letter said. "We hope you will agree that law enforcement must avoid any appearance of bias toward some citizens or hostility toward others."

The Shreveport Police Department has 15 volunteer chaplains in a city Pastor on Patrol Program, which hosted the vigils.

"A chaplain's employment, even if volunteer, is an unconstitutional endorsement of religion," the activist group's letter said.

The city does not plan to end the chaplain program, but the vigils will be discontinued.