As a non-SF resident, doing useful research inspired by 'google the current DA' is pretty laborious. I found https://www.sfgate.com/politics/article/Chesa-Boudin-San-Fra... which seems sensible on the face of it, and doesn't sound at all like he's "ensuring that criminals run rampant throughout the city".

The general problem of media assuming good-faith information from police is widespread and SF is no different from any other location in the US (or Canada for that matter).