I agree that it is the person's actions that matter in criminal court, not their thoughts and feelings.
To me, it seems there was a conspiracy of 4 people necessary to kill poor Dan: someone to order and pay for it, someone to contact the others, help plan it and distribute the money, someone to drive and someone to shoot the gun.
IMO, unless there's additional evidence such as, perhaps, Wendi and/or Donna chosing the day and time, manipulating Dan to be more easily found, forcing Charlie to do it, or sharing essential information that Charlie could not have found out on his own, I don't see, at this point, that those two committed any crimes. Hating someone, wishing they were dead, isn't a crime...actually killing him is.
JMO