Here’s a link to an indictment:
http://blog.bennettandbennett.com/wp-content/uploads/2015/11/Waco-twin-peaks-indictment-1.pdf
The indictment only uses “as a member of a criminal street gang” as the conspiring felony by which each is responsible for related felonies perpetrated by others.
Since when is simple membership a felony? No other “conspiracy to commit a felony” is specified. The indictment encompasses the named people on grounds of their participation at the Twin Peaks meeting, charging them all with an act which occurred at a different place & time for which most (all?) were not present at nor involved in.
By the indictment’s reasoning, Texas should be able to arrest & incarcerate (even execute) EVERY street gang member in the state for murder. That would solve many crime problems, but would unlikely stand precisely because the premise of the given indictment is absurd.
Either I’m still missing something (quite possible) or the DA is stretching _real_ far to nail them with _anything_ conceivable.