For extraordinary claims: 10 steps. Only then say 'we don't currently know' — a stronger conclusion than inventing certainty.
The 10 Steps
1. Document exactly what happened
2. Record the time and circumstances
3. Identify witnesses
4. Preserve evidence
5. Look for ordinary explanations
6. Look for coincidence
7. Look for psychological explanations
8. Look for technological explanations
9. Compare independent accounts
10. Determine what remains unexplained
The Standard
The last category should remain UNKNOWN, not automatically SUPERNATURAL. "We don't currently know" is a much stronger conclusion than inventing certainty.