Totalitarians try to use cases like this to take your rights away. Never forget how this impacts the innocent. If they can force this man to unlock his phone, they can force any innocent person to do the same. If the police think you’ve committed a crime, accessing your phone will never make them think you’re innocent. The absolute best case scenario is that they don’t find anything useful to their case. The worst case scenario is that they find your social media account where you called arson based last year, and they will use that against you.