"We have conflicting reports about the 211 Crew," he said, noting that the ADL has information that 211 Crew may operate with a paramilitary structure, but other information that indicates "they don't have much structure at all beyond a few shot-callers."
Both gangs are incredibly violent and lethal, the experts said, with the 211 Crew particularly violent to its own members, expecting them to maintain their membership and participation even after leaving prison.
"A 211 rule is that you must stay in the gang when you leave. You are expected to earn," Potok said.
Richard Ely, an attorney who has represented Aryan Brotherhood of Texas, admitted that the ABT expects members to stay loyal, and can become violent if they are not.
"Once you're on the inside, you're never out," Ely said. "And if they kick you out, they either beat you up badly or they could kill you based on what you've done. I don't know about any sort of retirement plan. Most of the older members are retired on the Uncle Sam system, serving life sentences."
"If you break the rules, if you do something that is not in the gang's best interest, a number of brothers will grab you, take you out to the woods and beat you, to the extent you will probably need to be hospitalized," he said. "And if you take your punishment like a man you're back in."
Members of early prison gangs, from when they began in the 1960s until about the 1990s, could often walk out of prison and leave their gang affiliation behind. But that is increasingly no longer the case, Potok said.
"It used to be quite normal for a member of a racist prison gang to shed his membership at the prison doors as he got out, and that was accepted. More and more that's hard to do. The price for leaving one of these gangs is death," Potok said.
Both the SPLC and the ADL emphasized that there are no known connections between the two gangs.
The ABT is estimated to have up to 3,000 members, almost entirely in state and federal prisons inside Texas, though there are branches in neighboring states. The 211 Crew is estimated to have a few hundred members only in Colorado state prisons.
Cooperation between the two is possible, especially since they traffic the same drugs, but not verified, Potok said.
Speculation of gang cooperation heightened when Clements' killer, Evan Ebel, died in a shootout with Texas cops.
"The most intriguing piece is when Evan Ebel got into a shootout with cops, he was 100 miles from Kaufman County. I know Kaufman County. There's not much there, so it is weird. It is an unusual place for someone to run there," Potok said.
Pitcavage emphasized that there is no evidence linking the murders, and pointed to the fact that Texas authorities are also looking into drug cartels, street gangs, and the possibility of a disgruntled inmate acting alone in the murders. The ADL also passed information to police about the Aryan Circle, a rival gang of the ABT in Texas.
"What does this all mean?" Potok asked. "These cases reflect the fact that prison gangs, which for many years were entirely confined to prisons, are increasingly spilling out onto the streets of our cities and towns around the country."