Sheriff's deputies said Anthony Garcia received more than $30,000 in fraudulent unemployment while in prison from 2008 to 2010.
They say Garcia's father and two girlfriends would get the checks, cash them and then deposit the money in the inmate accounts of Garcia and fellow gang members.
Garcia's father 47-year-old Juan Garcia, and girlfriends 45-year-old Sandra Jaimez and 25-year-old Cynthia Limas, were arrested Thursday on charges including grand theft.
Garcia was sentenced to prison in 2004 for killing a gang rival outside a Pico Rivera liquor store. He had the murder scene tattooed on his chest.