I sure hope so. It is a bit unnerving that others involved may still be on the streets. This is a horrific crime and I sincerely hope all involved are put through the justice system. My heart goes out to the surviving family members. May they be given strength.
I will go out on a limb and say there is probably not any evidence that DW's brother, the one with a violent criminal past, is involved, or any other hardened violent criminal. I really believe if others like DW were believed to be involved in the mayhem at the SS home, they'd be locked up right now.
I see two probable paths the investigation is taking, given the chatter in this board:
Others (with no known criminal history) who may be criminally involved, but who did not set out to engage in this magnitude of violent crime, who set out "only" to be involved in a property crime, possibly with the threat of harm, will be charged once the cases against them are strong enough for LE to tip their hand. This probably won't take long to sort out, but having the case ready for a DC jury is another story. In this scenerio, LE already has a great deal of evidence, but it isn't necessarily admissible in court and they must bolster their case.
Or, if this is a murder for hire scenario, I suspect the forensic accountants and detectives have their work cut out for them, and it's going to take a very, very long time to sort this out because DW isn't talking and neither is his benefactor.
I'm probably stating the obvious.