There is so much of this kind of stuff out there...as someone said before me:
The more I learn about people, the more I love my dogs.
It goes without saying that I am saddened by this. I wish I could say I'm surprised. It seems there are two kinds of animal owners (I can't even say pet owners, it is obvious those dogs were not anyone's pets). Those who take responsibility for the lives in their hands and those who do not. I wish there was a way to stop the latter group from ever having any animals as it always leads to heartache for the animals and adds to the overpopulation we are already experiencing.
I hope he/she is stopped before anymore are abandoned and that all are found.