That's not what would happen, though. The police will use this tech on poor people who can't afford their own attorneys, and public defenders are too overworked, underpaid, and/or cynical to try to push back against the system. On the off chance that a rich person gets falsely arrested due to this tech the prosecution will probably immediately settle out of court to avoid scrutiny. This same scenario has played out over the last decade or so with the Stingray device[1] in particular and various forms of warrantless (or essentially warrantless) wiretapping in general. Even if facial recognition tech is officially banned or restricted, it will probably be used secretly and covered up using parallel construction[2].

[1]https://en.wikipedia.org/wiki/Stingray_phone_tracker [2]https://en.wikipedia.org/wiki/Parallel_construction