this is it. boom, boom, boom, boom. >> they can't see his face from the camera but in a wired philly the trail isn't cold just yet. >> here we go. >> armed with this information detectives can tap into their private cameras in the days to come to try and catch their killer. >> if you can, take a snapshot. >> i took a snapshot. >> without you i am nothing. ♪ >> it's my final night embedding with the tactical force. and once again i'm with officers pinto and artiz. as we hit the streets, a job comes up on their computer. >> mentally ill personal apparently who's holding a female inside. refusing to let her go. the male's violent. >> how are you doing? i have a body camera. i'm recording.