Red Hand is a vigilante group roaming the US looking for criminals.
Formed in AZ04 by "Escorpion" they punish people who have wronged others. Victims are displayed as a warning and red painted handprints can be seen in the surrounding area.
As of episode "Heart of Darkness" it is known that Vasquez has been the leader of the Red Hand. As he is given mercy by Roberta, she is now in charge of the group.
As of "The Siege of Murphytown" all surviving members of the Red Hand were turned into Blends.