The NYPD had suspected New Jersey’s Masjid Omar Mosque, where jihadist Sayfullo Saipov reportedly worshipped, of having radical ties for over 10 years, allegedly keeping all its worshippers under watch.

Moreover, the FBI, which claims it had nothing to do with monitoring the mosque, interviewed Saipov as a potential Islamic terrorist in 2015, but ultimately let him go.

On Tuesday, Uzbek national Saipov killed eight people and injured at least 11 in a vehicle attack on the West Side of Manhattan on Tuesday.

“The New York Police Department has secretly labeled entire mosques as terrorist organizations, a designation that allows police to use informants to record sermons and spy on imams, often without specific evidence of criminal wrongdoing,” reported the Associated Press (AP).

Even in the face of Islamic extremist terrorism, Democrats such as New York City Mayor Bill de Blasio are vehemently against his NYPD labeling mosques terror entities, which entails heavy surveillance.

Designating “an entire mosque as a terrorism enterprise means that anyone who attends prayer services there is a potential subject of an investigation and fair game for surveillance,” explained AP.

NYPD officers began labeling mosques terrorist organizations around 2013, a move that would grant them the authority to conduct surveillance on mosques.

The previous year, the NYPD established a goal of monitoring every mosque within a 250-mile radius of New York, and placed the Masjid Omar Mosque on top of their surveillance list. “One of their priorities was the Masjid Omar Mosque on Getty Avenue, which the NYPD identified as a target in a 2006 report,” a 2012 NorthJersey.com report noted.

“The NYPD and New York City Mayor Michael Bloomberg have defended the surveillance [of mosques] operation as an effective way to root out terrorism, and the mayor and officials have said the police force operated within the law,” the report continued.

Nevertheless, the NYPD failed to ferret out the culprit of the recent crime and the FBI proved unable to affiliate the killer with any criminal act. Both law enforcement agencies failed to capitalize on the opportunity to thwart the attack years before it took place.

Referring to the interrogation of the culprit, ABC News explained:

Saipov was listed as a “point of contact” for two men whose [names] were listed in a Department of Homeland Security counterterrorism database and later overstayed their tourist visas, a federal official told ABC News. One was flagged after arriving from a so-called “threat country,” while the other vanished and was being actively sought by federal agents as a “suspected terrorist.” An official told ABC News that the FBI has since located him and he is not believed to have been involved in Tuesday’s attack.

After killing innocent people in New York on Tuesday, law enforcement shot the jihadist. He is currently recovering from his wounds and reportedly had no qualms expressing pride for the brutality he had inflicted upon the inhabitants of the country that had granted him a home and the victim’s family.

While mosques are places of worship, they sometimes also serve as fertile ground for the dissemination of radical and extremist ideology.

The Masjid Omar Mosque of New York is located in one of the largest Muslim and Arab communities in the region, which is where some of the 9/11 hijackers reportedly lived temporarily.

Authorities reportedly found a handwritten note from Saipov claiming his terrorist attack was a tribute to the Islamic State (ISIS/ISIL).

Many Uzbeks are fighting on behalf of ISIS against the Taliban and Afghan forces in Afghanistan.

Although the “terrorism enterprise investigations” (TEIs) into mosques allow the NYPD to carry out surveillance for years, it has not reportedly yielded a criminally charged mosque or Islamic organization with serving as a jihadist organization.

Nevertheless, some of the most notorious jihadists are known to have attended U.S.-based mosques.