The Jewish Mob is a criminal organization which deals in diamond trading. Isaac Roth, a Hasidic Jew, appears to be the boss of the operation, with Mori Green, a mainstream Orthodox Jew, as the underboss and his right hand man. All members of the Jewish Mob have suits with ties, with non-matching jeans. They can appear in two forms: A bald fat man, or one smaller, with short hair. Their vehicle of choice are black PMP 600's. The LCPD database says that Roth, Green and the Jewish Mob in general make frequent deals with African warlord Claude Wome, a dealer in conflict diamonds. Their favorite radio station is Electro-Choc since its the default radio in their cars and both radios in the Majestic Hotel are turned on to it.
Events of GTA IV and TLAD
In their first appearance, which coincidentally is the Impossible Trinity trio of missions, they are dealing $2,000,000 with Ray Boccino for diamonds. Ray sends Niko Bellic and Johnny Klebitz to do the deal. Since the diamonds were stolen from Tony Prince and Luis Lopez, Luis appears on the scene and ambushes the deal, killing Mori Green and two Jewish goons in the process. The museum turns into a firefight as Luis steals the diamonds, Johnny steals the money and Niko flees with nothing. A lot of Jewish mobsters are killed in process.
Later, Issac Roth blames Ray Boccino for botching the deal and taking the money and diamonds for himsel. After an argument via the phone, Roth threatens Boccino. In response to this, Boccino sends Niko Bellic to kill Roth and his diamond dealers at the Majestic Hotel rooms. Niko succesfully completes the task and the whole Jewish Mob is probably wiped out.