Young couple goes on van tour of US, boy comes back with van - no girl

As far as the way the cops handled the Aug. 12 stop -- since everyone wants to just blame those cops for what happened later -- it's VERY possible that they saved her from being murdered THEN by separating them for the night. A "mandatory" arresting policy would have resulted in Gabby being arrested that day based on how their side-of-the-road investigation was shaping up, not Brian.

But if that 9-1-1 call had not happened, if those cops never made that stop interrupting whatever crisis was happening between that couple, it's VERY possible that things would have continued to escalate on THAT day as apparently they did 2 weeks later.
I don't have the sources handy, but the dispatcher never told the cops that it was reported in the 9-1-1 call that he was hitting her. When they arrived and talked to both parties, the story was they she scratched him.

Also, one of the cops took her aside before letting them go and advised her to get out of this toxic relationship.

I really don't know more what they could have done given the circumstances.