Mafia

The Mafia, allying with Mello, increases its influence and intends to possess the Death Note and gain power; How to Read states that the organization is "being used by Mello."

Rod Ross
Rod Ross (Rodd Los in the Japanese version), real name Dwhite Gordon (Dwhite Godon in the Japanese version) is the head of the mafia. Ross follows Mello's orders. His name is easily known, so Light kills him.

Masaki Aizawa voiced Ross in the anime. Brian Dobson plays Rod Ross in the English Version. His name is also mentioned in L: Change the WorLd as the leader of an arms syndicate who deals with the mafia.

When asked by an interviewer who the most "evil" character in Death Note is, Ohba replied Ross, citing that Ross is "pretty darn evil" as he is the leader of the mafia.

Jack Neylon
Jack Neylon, whose real is name Kal Snydar (Kal Snyder in the Japanese version), is a member of Mello's gang. He is the holder of Sidoh's Death Note after it is given to the gang by the Kira investigation team. Before Mello joined, he was involved in drug trafficking and illegal weapons sales; neither charge stuck due to lack of evidence, despite four separate arrests. After Sidoh tracks down his Death Note, Jack performs the eye trade with him. Light uses the Death Note to have mail him the address of Mello's hideout. He is voiced by Takashi Matsuyama in the Japanese anime and Ted Cole in English.

Other mafia members

 * The mafia uses Zakk Irius (he uses his real name) to converse with the Japanese police at the airport. The organization kills Irius after he guides Soichiro to the correct aircraft. He dies by heart attack when the airplane lands; his gang wrote his name in the Death Note.
 * Glen Humphreys (Gurren Hangfreeze in the Japanese version), real name Ralph Bay, is a veteran gang member. The Death Note kills him prior to the police raid.
 * Rashual Bid (Rushuall Bid in the Japanese version), real name Al Meem, is a veteran gang member. When Kira eliminates the gang he dies with most of the members.
 * Miller is a member who was used as a test subject as to whether the Death Note was real during the exchange. He was killed because he was stealing drugs from the gang to sell, and was described as an "incompentent guy".
 * Jose is not affected by the Death Note instructions that kill the other members. He fakes his death and fatally shoots Soichiro, he later dies when the rest of the Japanese Police enter the room and shoot him.
 * Roy and Skyer are not affected by the Death Note instructions that kill the other members. They attempt to retrieve the Death Note; the task force disarms and subdues the two, they later (presumably) die when Mello blow up the entire building.