His endless talk of violent "jihad" so alarmed worshippers at the local mosque, that they took out a restraining order against him.
Monteilh spent 15 months pretending to be Farouk al-Aziz, a French Syrian in search of his religious roots.
"They got a guy, a bona fide criminal, and obviously trained him and sent him to infiltrate mosques...
After being given the code name "Oracle", he was told to root out radicals among the region's 500,000 practising Muslims.
"We started hearing that he was saying weird things," said Omar Kurdi, a Loyola Law School student who trained there.
Niazi appeared to agree with the idea, and the tape was subsequently used as evidence in the terror case against him.
Soon after the restraining order was obtained, in June 2007, the FBI attempted to cut their ties to Monteilh. »