> Interestingly, if they then release the full video which shows nothing, then suspicion's around the overall case will presumably be calmed.
Sadly their actions have created suspicion. Further releases of video will be doubted by a wide range of people, from calm but cautious scrutineers to rabid conspiracy theorists.
Absolutely. OTOH, the far weightier suspicion is around the eventual death of Ms. Bland. An effective PR strategy might be to do something relatively ancillary that heightens the overall degree of suspicion. You then unequivocally address the ancillary issue (i.e. by rleasing the full video), which has the effect of reducing suspicion overall, including on the far weightier issue. That is, people think "Hey, maybe these guys aren't so bad. Maybe we are just jumping the gun".
Not saying this is happening. But, if the full video suddenly comes out and is "all-clear", then the police department will certainly receive that benefit, whether intentional or not.
Sadly their actions have created suspicion. Further releases of video will be doubted by a wide range of people, from calm but cautious scrutineers to rabid conspiracy theorists.
Truth doesn't matter at that point.