I can see many valid uses of facial recognition,
probably the best use is with CCTV footage to track a suspects movements away from a crime, or to help identify a criminal against a database of convicted criminals, basically doing what human eyeballs do now...
But that is why we need legislation restricting its usage, especially use by the police and government, they are much less trustworthy than any private corporation.
I think if you are innocent then you should not have bio-metrics stored in any police database, this includes all situations such as Arrested but released without charge, charged but charges dropped before trial, charged but found not guilty at trial.
And even if found guilty, I think you should be removed from the databases a set time after the sentence has been served.
I even think that it is not generally in the public interest for convicted criminals details to be released to the public, I believe everyone has the right to anonymity. (the daily mail would be upset)
The whole criminal justice system is flawed, it harms the innocent, prevents rehabilitation of criminals, and doesn't address the root causes of crime.