"He was the first Kurdish cop, so he made us all proud," Hamid Hasan, the owner of House of Kabob restaurant in Nashville said.
Investigators say Suleyman lied on his application about who he was and who he associated with.
Once employed, Suleyman used the Tennessee Bureau of Investigation's computer program to look up fellow gang members, which is against policy.
Investigators busted Suleyman hanging out with Kurdish Pride gang members at House of Kabob.
Police had previously busted those gang members for illegally selling guns and drugs.
But Suleyman continued to associate with them, police say.
Pictures uncovered by a search warrant show Suleyman flashing gang signs and wearing the gang's colors before he even joined the force.
"It's bad because he did so much for this community, not for the Kurdish community, the whole community," Hasan said, insisting in an interview with WSMV that no gang activity ever happened at his restaurant.
"I am very surprised, honestly to god, I am so mad too because this is not good for nothing."
An investigative report describes House of Kabob as a sort of nexus of KPG activity that employs KPG gang members.
Suleyman resigned in March.
In 2017, Metro Police Chief Steve Anderson praised Suleyman for busting a Mexican heroin distribution ring.