iPhone users: recording cops? Use Emergency SOS features to disable biometrics, but still record
You can use the Camera without unlocking the device, and disabling the biometrics means no one but you (or anyone else who knows the pin) can access the phone, in case of any eventualities.
Go to the Emergency SOS screen.
On older iPhones, press the Power button 5x quickly.
on iPhone 8 and newer, hold Power and a Volume button.
Cancel out of this screen. You will be taken to your Home screen, where only your PIN can unlock your device. Back out of the PIN entry screen, and you can swipe between Home and Camera.
Photos and Videos are saved to the Camera Roll, but CAN be deleted if the phone is still awake. They are saved behind the PIN once you press Power or Home.