Leading Republican candidate Donald Trump told MSNBC’s “Morning Joe” the government needs to conduct surveillance on mosques following the deadly attacks in Paris.

“We’re going to have to watch and study the mosques because a lot of talk is going on at the mosques,” Trump said. “And from what I heard, in the old days, meaning a while ago, we had great surveillance going on in and around mosques in New York City. I understand our mayor totally cut that out. He totally cut that out. And I don’t know if you’ve brought that up, and I’m not sure it’s a fact, but I heard that under the old regime we had tremendous surveillance going on in and around the mosques of New York City. And right now that’s been totally cut out.”

After September 11, 2001, the NYPD’s Intelligence Division surveilled mosques and Muslim religious and community leaders, student associations, organizations, businesses, and individuals.

In 2007 the division released a report, “Radicalization in the West: The Homegrown Threat,” that pinpointed a number of “radicalization” indicators, including “wearing traditional Islamic clothing [and] growing a beard,” abstaining from alcohol, and “becoming involved in social activism.”

The NYPD was responsible for creating the perception of Muslim radicalization through its “create and capture” surveillance method.

Many of the techniques used by the NYPD were perfected by the CIA. In 2011, the CIA sent a senior officer to work as a clandestine operative inside police headquarters, according to the Associated Press.

In 2012 Shamiur Rahman, an NYPD informant, said he was under orders to “bait” Muslims into saying inflammatory things. Rahman also said he intentionally misinterpreted what people said at mosques and Muslim student groups to please his NYPD handler and make more money.

“The FBI and other law enforcement agencies like the New York Police Department [NYPD) have used threats and coercion to beef up their army of informants,” writes Alex Kane. “In the post-9/11 world, informants have been a major tool law enforcement has used to infiltrate Muslim communities in the hopes of picking up tips on terrorism. Since the September 11 attacks, the FBI has put more than 15,000 informants on its payroll.”

The FBI has played a major role in baiting Muslims and has also arranged a number of fake terror plots.

“In some cases the FBI may have created terrorists out of law-abiding individuals by suggesting the idea of taking terrorist action or encouraging the target to act,” a report released by Human Rights Watch noted last year.

Trump’s claim New York Mayor de Blasio “totally cut” the controversial NYDD surveillance program is not entirely true.

In 2014, after lawsuits were filed in response to the program, the NYPD reportedly shut down its Demographics Unit responsible for spying on mosques and Muslims. In May of that year, however, the NYPD began to use its Citywide Debriefing Team to recruit Muslims as informants.

Although de Blasio said during his campaign he was “deeply troubled” by the program, he supported it after taking office. “Based on what I’ve learned, I believe that the NYPD is currently limiting its work to the pursuit of specific leads and that there is a substantial legal review process connected to those decisions,” he said.

In January, following the Charlie Hebdo murders in Paris, former New York Mayor Rudolph Giuliani called on de Blasio to resume the practice of placing NYPD informants in mosques.

“The mayor of New York, one of the first things he did was he pulled all of the police out of the mosques. Well, you know who put the police in the mosques? I did. You know who increased the number of police in the mosques? Kelly and Bloomberg,” Giuliani told Fox’s Greta Van Susteren. “And why did I do it? Because the first attack on the World Trade Center in 1993 was organized in a mosque. The blind sheikh, who went to jail for a hundred years, was planning to blow up our subways in a mosque.”

Giuliani did not mention the FBI’s role in the 1993 World Trade Center plot. A Muslim informant organized the bomb plot with the “supervision” of the FBI and the District Attorney as part of a classic entrapment setup. Several of the bombers were trained by the CIA to fight in the Afghan war. Internal CIA documents later concluded the agency was “partly culpable” for the bombing.