BoozillaAppeals court rules that cops can physically make you unlock your phone
dependencyinjectioniOS users can press and hold the power and volume up button until the emergency call screen appears, then release. You now have to enter your PIN / Password to unlock again and not use TouchID / FaceID. Good luck trying to get me to tell you the code.
You can hit the power button 5 times to accomplish the same thing as well.
Your comment and the one above should be shared widely these days. Everyone should know this.
On Android the lockdown option shows next to the shutdown, requires a code instead of a bio