The threat was menacing: the celebrity Rabbi Shmuley Boteach “deserves death,” wrote a Brooklyn Jewish male in an April 2007 posting on a extremist web site. The next year, the same man wrote on Kahane.org: “Someone shoot Shmuley Boteach,” the well-known Rabbi who is a close friend of New Jersey Senator-elect Corey Booker, a former spiritual adviser to Michael Jackson and the person Samantha Power feted to prove she was a supporter of Israel.

The New York Police Department (NYPD) used the postings made on the public forum to help justify why a “terrorism enterprise investigation” needed to be opened into Kahane Chai, according to documents obtained by Tablet magazine’s Adam Chandler. But while an investigation was opened, the NYPD’s Intelligence Division never requested the authority to enter into a synagogue where information could be gleaned about Kahane Chai, a far-right Jewish group founded by Meir Kahane that has been linked to deadly violence, including plots in the U.S. The Intel Division also never relayed the threats to the man most interested in knowing about them: Boteach himself.

The methods of investigation into a specific Jewish terror threat stands in sharp contrast to how the NYPD investigates terrorism in the Muslim community. The New York police appear never to have entered into a synagogue in relation to the case, despite there being a number of synagogues who openly celebrate Meir Kahane every year. But when it comes to the Muslim community, mosques are fair game. At least a dozen mosques are being investigated as “terrorist enterprises,” a designation that allows the police to infiltrate religious institutions and record what imams are saying. What’s more, the “terrorism enterprise investigations” (TEI) launched into mosques are justified using much more innocuous reasons when compared to the TEI launched into Kahane Chai.

“It seems to me, on the face of it, a difference that is pernicious. In other words, that it is treating Muslims differently and allowing investigations to range much more broadly when it comes to Muslims,” said Jethro Eisenstein, a civil rights lawyer involved in the Handschu case, the legal decree that governs how the NYPD conducts surveillance. “It appears to me that there is a double standard being applied.”

According to Tablet, the investigation into Kahane Chai dates back to early 2008, when Israel’s Shin Bet contacted the NYPD to request information on 25-year-old U.S. born Israeli who was a leader in the Kahane-linked Jewish Legion. After conducting surveillance on the man and then perusing Kahane Chai’s websites, top NYPD Intelligence officials requested the authority to investigate the group as a “terrorist enterprise.” But the NYPD didn’t take the investigation seriously. They never told Boteach his life may have been in danger. And they only launched the investigation as cover, according to Adam Goldman, the co-author of the new book Enemies Within: Inside the NYPD’s Secret Spying Unit and bin Laden’s Final Plot Against America, an eye-opening look into NYPD surveillance.

“They only opened up the investigation because it looked bad, because all the other ones were directed at Muslims or Arab-Americans,” Goldman told me, relaying information he received from a source familiar with the NYPD investigation into Kahane.

Regardless of the validity of the investigation, though, the documents posted by Tablet reveal the vastly different ways the NYPD investigates terrorism threats. And it all has to do with religion, despite the protestations of Mayor Michael Bloomberg.

NYPD Chief Ray Kelly defends the investigation of mosques by saying, “we follow leads wherever they take us. We’re not intimidated as to wherever that lead takes us. And we’re doing that to protect the people of New York City.” But a close look at the documents reveals that leads in relation to specific terrorist threats are not used to justify “terrorism enterprise investigations” into mosques. There’s a much lower standard. In comparison to the specific and deadly threats from Kahane Chai members on websites, the NYPD has launched TEIs into mosques where no similar deadly threat has emanated from.

One document posted by Goldman and his co-author, Matt Apuzzo, shows an NYPD request to extend a years-long TEI into Tablighi Jamaat, a South Asian-dominated, conservative Islamist movement devoted to spreading the religion and bringing disaffected Muslims back into the fold. While the movement is nonviolent, terrorist plotters have used it as a cover to mask their intentions. But their North American headquarters, the Queens-based Masjid Al Falah, hasn’t been linked to terrorism. The NYPD infiltrated it anyway.

They based their TEI on things like the mosque leadership allegedly preparing, distributing and utilizing “false Pakistani passports and other false identification documents to facilitate the illegal entry of aliens into both the United States and Pakistan.” But in contrast to the TEI into Kahane Chai, there was no specific terror threat from the mosque the police were investigating. Masjid Al Falah has been infiltrated since at least 2006, according to another NYPD document, but the investigation has never progressed to indicting the mosque as a terrorist enterprise. There has been no case built against any other mosque investigated as a “terrorist enterprise.”

Other NYPD documents show an obsessive focus on the Muslim community while ignoring the Jewish community. In 2007, the NYPD’s Demographics Unit mapped out “Syrian locations of concern.” But despite the majority of the Syrian community being Jewish, they were excluded from the document. “This report will focus on the smaller Muslim community,” the document posted by the Associated Press reads.

NYPD spying “wouldn’t fly in the Christian community,” Linda Sarsour, executive director of the Arab American Association of New York, told me recently. “It wouldn’t fly in the Jewish community. It wouldn’t fly in any other religious community. Why is it okay that it’s happening to Muslims?”