Sad story. Ms. Baca probably has never had much dealings with the cops.
She requested that she be notified when they were on the way - unlikely to happen.
She assumed the officer would respond knowing the reason for her call - it could well be that never happened either, given the cop climbed her fence. Maybe the cop thought the caller was in a potentially bad situation. Maybe.
While I can’t blame her for doing so, personally I would never leave aggressive, or for that matter, any, dogs outside even in the back yard, knowing people were on the way over - particularly cops that routinely don’t respect private property.
There was no justification for the cop to trespass, if he truly did not know why he was called to the residence.
Points well made!