[imtringued]

I think this is motivated by the fact that storing video from every body cam is too costly for little gain. The police departments that have well trained staff and nothing to hide adopt them with no effect on officer behavior. Police officers get away with bad behavior because of no accountability. When they make a mistake and kill or injure an unarmed person there is always another officer that will cover them. When you interview all the officers that were supposedly at the crime scene you get contradicting stories precisely because they weren't actually there. Therefore the focus is now on the tactical benefits of body cams.

In video games there is often a "kill cam" that shows you where an enemy attacked you from. This information is often used to spot camping snipers and then sneak up to kill them for revenge. If the police can utilize the body cams correctly the maximum number of casualties should drop drastically.