befer before a city-wide roll out and in 2013 one of the most violent cities in philly was chosen, the 22nd district which recorded 217 shooting victims that year. so these are the police body cameras? >> yes. these are the taser exon. >> this is officer mcfadden, the man in harj of getting the body camera program up and running. >> they put this on a clip on their shirt. very simple operation. hear two beeps. so you'll see video start from inside the car. so they film from beginning to end. >> so they're not on for 24 hours? -- >> no, for a job. if you're outside, there's no