I'd also add that failure to do so should result in a $1,000 penalty, half of which should go as a $500 reward to anybody who reports the case (photo would suffice as proof). Officers should have their whereabouts tracked via there phones for accountability purposes, which could be used to verify such reports or identify officers.
How do you enforce the penalty if the perpetrator is anonymous? Fine their management instead? That doesn't work when the executive branch is above the law.