A group of former CIA, FBI, DEA and military intelligence officials is urging presidential candidates to reject torture as an interrogation tool.

“Torture is not only illegal and immoral; it is counterproductive,” the officials said in an open letter to the candidates released Wednesday by Human Rights First, a nonpartisan group with offices in New York, Houston and Washington, D.C.

 “It tends to produce unreliable information because it degrades a detainee’s ability to recall and transmit information, undermines trust in the interrogator, and often prompts a detainee to relay false information that he believes the interrogator wants to hear,” wrote the interrogators. “It also increases the risk that our troops will be tortured, hinders cooperation with allies, alienates populations whose support the United States needs in the struggle against terrorism, and provides a propaganda tool for extremists who wish to do us harm.”

The group includes Frank Anderson, a former chief of CIA operations in the Middle East and South Asia, and Michael Rolince, who headed the FBI’s International Terrorism Operations Section in the run-up to the September 11, 2011, attacks on New York and Washington, D.C.

Anderson said  “the intelligence community has long known that national security is best served by humane interrogation,“ according to a statement released by Human Rights First. “When it comes to protecting American lives, torture actually makes us less safe.”

It’s not the first time Anderson, Rolince and other former intelligence officials and interrogators have publicly urged presidential candidates to reject the use of waterboarding, beatings and other hard measures on detainees. In 2008, many of the same ex-officials released a paper, “Principles for Effective Interrogation,” and implored candidates to adopt it. They did so again in 2014, and according to Human Rights First, reached out to candidates on the issue directly and privately by letter last September.

The group released the letter on Wednesday because they “are alarmed by recent rhetoric about torture and wanted to make their position,,,clear and public,” according to Corrine Duffy, a spokesperson for Human Rights First. “They do not oppose or support any candidate, but do want the facts out there about torture.”

The group’s main target would seem to be Donald Trump, the New York real estate tycoon now leading the Republican field. Trump has repeatedly pledged to reinstate waterboarding and ”a hell of a lot worse” if he wins the presidency.

Last week, however, the CIA’s former top lawyer predicted the spy agency’s rank and file would resign rather than resume waterboarding and other “enhanced interrogation techniques.”

“I think certainly many of those who were connected to the EIT program over its six years’ span—and hundreds are still there—would resign or retire rather than have to go down that perilous road again,” John Rizzo told Newsweek. “Who could blame them?”