gathered for a public safety meeting with supervisor jeff shehee and others. >> was this a fall? was this a push? was the person struck and how exactly did they end occupy p up on the ground. >> surveillance video from a nest camera shows the mother crossing 28th street on sanchez. after she walks out of frame you can hear her screaming and seconds later her baby crying. somebody appears to run up the hill after the attack. >> nobody should be a victim of a senseless crime like this. >> barb says based on the c.t. scan, doctors believe she was hit on the let we the suspect with something like a hammer. one from next door of a mother in a mission hit with a rolled up newspaper to the pack of her head. >> we're casting a wide net. we're keeping an open mind. >> they're letting police know. >> this is part of building trust with the community to let them know that we are going to be with you in these extreme circumstances, but we're also with you day to day. >> investigators are earn couraging anyone with video to contacts them. also, a coordinator from s.f. safe to let them know s.