(CBS News) -- Investigators are following a number of leads in the deaths of Kaufman County, Texas, District Attorney Mike McLelland and his wife, Cynthia.
One of these leads is the possible involvement of a white supremacist group.
Charles Lee Roberts is known as "Jive". Larry Max Bryan goes by "Slick". Federal prosecutors say they are two of the generals who govern the ruling council of the Aryan Brotherhood of Texas -- a violent white supremacist gang, largely based behind bars.
ABT, a "whites only" gang, was founded in the early 1980's. Its 4000 members show their allegiance with swastikas and other tattoos -- some inside their lower lips.
Many members are current or former convicts. "Slick" Bryan, for example, has been in prison for nearly 22 years.
In a sweeping federal indictment last November, Bryan, Roberts and 32 other alleged gang members were charged with racketeering and crimes ranging from drug dealing to murder.
Lanny Breuer was the Assistant Attorney General who led the crackdown.
Last November, Breuer said: "Today's indictment represents, ladies and gentlemen, a devastating blow to the leadership of ABT."
But a new report from the Texas Department of Public Safety says the Aryan Brotherhood of Texas remains a dangerous threat with a "large membership" presenting a "consistent level of violence and other criminal activity."
ABT makes money selling methamphetamine both inside and outside of prisons but prosecutors say another mission is violence, used to protect fellow members or to avenge perceived mistreatments.
Assignments come from the generals and are passed down down to enforcers.
Prosecutors say one order, "SOS", means "smash on sight". That's code for assaulting a rival gang member.
Then there's a "green light", sometimes simply called an "X". That's a hit, an assignment to murder a rival or an ABT member who has violated the gang's rules.
Kaufman County District Attorney Mike McLelland and his wife, Cynthia, were "targeted" in killing
Over 30 years the Aryan Brotherhood of Texas has been linked to some 10 kidnappings and more than 100 murders, many of those behind bars and away from public scrutiny.