Interesting. I don't have a password. And I defy you to unlock my phone.
The question is "Can I be forced to unlock my own phone? Under what circumstances? Under what circumstances can I be charged for refusing to do so?"
If you haven't already guessed, I use a complex swipe pattern, one that uses all nine points and cannot be determined from reading the grease streaks, at least not easily. I know this because I moved to the current pattern after my daughter unlocked my phone by reading the grease streak. I changed the pattern and handed it back. It even used the previous pattern. She took one luck, uttered an obscenity, and handed back the phone.
Can I be compelled to describe how to perform the swipe? To describe the pattern? To guide the agent? Interesting questions....