I just want to know why they would foster a beautiful pitbull and then just put it down, to me that's murder,

The aim of ACS and organizations like SAPA (San Antonio Pets Alive) is to turn SA into a no kill city like Austin. In SAPA's first year, approximately 70% of the animals scheduled for EBI were saved through fostering and adoption. Sadly, San Antonio has a different mindset than Austin so it's hard to get people to adopt (a lot of dogs are surrendered because people can't afford to keep them anymore).

But he was already fostered out they went to pick him up and y'all put him down

Too many animals, not enough space, money, or compassion.