According to Breitbart news, the Waco DA charged 106 of the bikers under identical indictments all alleging the same facts in each 106 cases. All the charges are for life sentences, or between 15 to 99 years if a life sentence is not issued. Naturally, the grand jury accepted all 106 indictments, which will now go to trial.
Only 9 people died, so 106 people can't be guilty of the actual killings. In fact, the charges don't appear to charge any of the 106 with any particular killing. The charge is for a kind of collective responsibility for the deaths due to participating in 'organized criminal activity' that resulted in the 9 deaths.
As of yet we haven't seen any evidence showing who was responsible for any of the killings, so it's interesting to me that -- after months and months of investigation and interrogation -- no one has been charged with any particular act of violence. In fact, I'm not sure how you could hope to prove a collective responsibility if you can't first establish a personal responsibility. In order to say that every member of the Cossacks MC was collectively responsible for a death, shouldn't you have to show that some member of the Cossacks MC was responsible for it?
There are still 80 bikers who haven't been charged at all. Perhaps 'the real killers' are among them, and Waco just wanted to get the easy cases out of the way first.