Think about it. Not one family member has begged this guy to turn himself in. It has nothing to do with their involvement with anything other than being terrified he's in danger. Nothing. They could still maintain their right to remain silent on matters concerning their possible involvement, but at least use the media to reason with their son. Absent that simple gesture of humanity, who cannot but think some kind of pervading disfunction factors into the entire situation.
They have a missing, endangered adult child, with an enormous bounty affixed to him. That IS dangerous. In fact MORE dangerous than the possible penalty for the crime he's currently charged with. The media is begging for them to use the opportunity to speak. Nothing.
Brian needs their help and they're opting for self-defense.
MOO