@Pleistocene891 Peregrine should generally show feathers down most of the legs, and have a dark mask and dark coloration from cap down the neck to the back, which this bird appears to lack. Accipiters (Sharp-shin/Cooper's hawks) have a long tail as this bird seems to, and a dark cap, but should be much redder on the front than this bird appears to. My best guess based on your given location is either Sharp-shin or Cooper's, though I'm not real convinced from this photo. It strikes me more as a caracara in appearance, though they are not present in California normally, and our native species isn't a great match either.
