I think they killed the people, maybe the Father who worked in LT Care Centers was going to spill the beans on the JABS killing people, since they say he was a caring man, so they murder him and his family, and set up the false Flag event to cover up the murders.

how does a witness see the truck fly by her near the event, then see the people waving arms where the victims were, while police are giving them chest compressions?

This is staged IMO and something Bigger is about to happen.