Damages in civil trials are roughly "compensatory," and vary greatly between plaintiffs. The life of a young person is worth more based on expected earnings over their remaining life, than the life of a "similarly situated" old person. The earning potential of a professional is greater than the earning potential of a laborer, and so on. Very little in the way of pain and suffering, given the mode of death.
In order to prevail, the plaintiff has to prove that the defendant's actions were a proximate cause of the death. This is relatively easy to show for the shooter, and considerably more difficult to show that "the reasonably foreseeable outcome" of riding to Twin Peaks is a proximate cause of a death.
Well at least the widows might also claim “loss of consort”.
As for “pain and suffering”: that of the widows, the parents, even the siblings is something that no dollar value can approach, over the years and decades that the suffering will continue.
And then there is “contributory negligence”. If the bikers rode to the call, contributing to the deaths, those who were killed also rode to the call . . . contributing to their own deaths. Such as Campbell, who left money to his ex-wife for his kids before he rode to Waco, apparently not expecting to come back; very tragic.
Can the families sue the Cossacks and Bandidos as entities, or the Confederation?