I don't think they can sue him again. The difference in the "threshold of proof" between the civil case and criminal case is really wrong, anyway.
Further, no matter how much anyone may believe he is guilty, myself included, he was found not guilty in a court of law. There's no doubt the state screwed the pooch on the case in so many ways it cannot be counted, and they lost. The jurors admitted their bias as well, another failure of the state. But still, he was found not guilty.
They should not have been able to bring a wrongful death suit against him.
All that was was an attempt, albeit successful, at circumventing the jury verdict in the criminal case. Whether anyone believes he was guilty or not, that was wrong. All it means is that being found not guilty doesn't mean a person can't be punished anyway and with less proof than was used in the attempt to convict them.
I think he most likely did it. It probably should have been an airtight open and shut case. But it wasn't. That means there was not overwhelming proof. Or at the very least it was very poorly presented. But if they can't get a conviction, they shouldn't punish the person they couldn't convict.
