officer brian hernandez was one of several unitssponding to a call about a suspect in east oakland, wanted in a robbery and attempted murder. >> good. but our cameras weren't the only ones catching the action. each officer wore one of these, another set of eyes, reporting everything that happened. >> shoes or anything on? >> i'm sorry. >> hold on. now. back. sit down. come on? >> i can't talk to my son. >> give us a second. we will let you go talk to him. >> that's totally unrelated. >> oakland is more than 3500 police departments nationwide using body cameras. they have been taking the plates of dashboard cameras because they go where the officer goes. >> officers were able to capture individuals either discarding firearms or making incriminating statements in regards to their involvement until crimes that would have been the officer's word against the subject's word but the lapel camera made this clear and evident. >> our policy is if you are investigating any kind of crime or there is a potential of an encounter with someone in detention, we are supposed to activate it. >> how has the l