Her reaction may have saved lives by “freezing” the perp. I am supposing she knows the victims or possibly related to one of them. Or possibly she is related to the perp. Like you said though, it seems her concern is with the victims.
The blonde woman, just to the right of center, about a third of the way down, wearing a light blue or white blouse or jacket, doesn’t appear to have reacted at all, as if nothing unusual is going on.
