A police department in a Texas Bible Belt community has placed large "In God We Trust" decals on its patrol vehicles in response to recent violence against law enforcement officers, drawing criticism from a watchdog group that says the decals amount to an illegal government endorsement of religion.

The decision by police this month to unveil the phrase in Childress, an agricultural community of some 6,100 people at the southern edge of the Texas Panhandle, follows a similar move by dozens of other police agencies elsewhere in the country.

Police Chief Adrian Garcia said he decided to add the decals in response to recent attacks on law enforcement personnel that have received broad attention, including the Aug. 28 killing of a sheriff's deputy who was shot 15 times at a Houston-area gas station.

"I think with all the assaults happening on officers across the country ... it's time we get back to where we once were," Garcia told the Red River Sun newspaper. He did not respond to an Associated Press request for comment.

The Law Enforcement Officers Memorial Fund notes that eight officers have been shot and killed in the U.S. in the last month — and four died in the span of 10 days — but shooting deaths of officers from January through September of this year were actually down 13 percent compared to the same period last year.

Other law enforcement agencies have cited different reasons for adding the phrase to their vehicles. Mark Nichols, the sheriff of Randolph County, Missouri, said he had it added to his department's fleet in July out of a sense of patriotism.

"It's our nation's motto and we want to be patriotic toward our country," Nichols said.

He said the Missouri Sheriff's Association previously voted to support adding "In God We Trust" to sheriff's vehicles across the state.

In fact, of the dozens of complaints about the decals lodged in recent months by the Wisconsin-based Freedom From Religion Foundation, about half were sent to law enforcement agencies in Missouri. Departments in Arkansas, Florida, Kentucky, Virginia and elsewhere also received complaints from the foundation, which says it will consider suing but acknowledges it can be difficult finding a plaintiff willing to be publicly identified as challenging the use of the phrase.

Gary Parsons, the sheriff in Lee County in Virginia, said his office spent a total of $50 to have the decals added to about 25 vehicles. He said many people feel their belief system is being trampled and that adding the phrase is a way of pushing back.

"It's not only a symbol of moral values but also a symbol of patriotism," he said.

In its letter to Nichols, the foundation said, "Statements about a god have no place on government-owned cars. Public officials should not use their government position and government property to promote their religious views."

The letter cites the Pew Research Center when it goes on to say that 23 percent of Americans identify as "nonreligious," up 8 percentage points from 2007.

Rebecca Markert, a senior staff attorney for the foundation, said the First Amendment prohibits government from establishing or even preferring a religion. The growing number of law enforcement agencies adding the phrase to vehicles amounts to a violation of separation of church and state, she said.

While Nichols and other leaders say their communities have been supportive, Markert says it's important to protect the interests of those whose views may not be broadly supported , such atheists and agnostics.

"The Bill of Rights was passed to protect minority rights against the tyranny of the majority," she said.

Jeremy Dys, senior counsel for the Texas-based Liberty Institute, a law firm that specializes in issues of religious liberty, said the U.S. Supreme Court and lower courts have repeatedly allowed the phrase and other religious overtures as "part of the country's history and heritage."

This is why courtroom oaths are protected along with legislative prayers, the Pledge of Allegiance and other acts steeped in religious symbolism, he said.

Charles Haynes, vice president of the Religious Freedom Center of the Newseum Institute in Washington, D.C., explained "In God We Trust" began appearing on federal coins in the Civil War era, and Congress in 1956 approved it as the national motto.

The foundation notes in its letter to Nichols that the history of the motto has "no secular purpose," explaining that it was adopted during the Cold War as a reaction to the "godliness" of communism. It says the country's original motto, E Pluribus Unum, was purely secular.

Haynes said pitched battles over religious phrases likely will increase as groups like Freedom From Religion become better funded and gain broader support.

"I think we're going to see a growing number of fights over these symbolic references to god by government," he said.