Unwritten Rules for Forensic Scientists

Forensic science is not just about laboratories, instruments, and scientific techniques. It is also about integrity, objectivity, patience, and responsibility. Some of the most important lessons in forensic work are not always written in textbooks—they are learned through practice and experience.

1. Never let the conclusion come before the evidence.
2. Document everything—you may not remember it later, but the record will.
3. If you didn’t document it, you may not be able to prove you did it.
4. Never alter evidence to make it fit a theory.
5. A negative result is still a result.
6. Know the limits of your method—and admit them.
7. Never say “100% certain” when science cannot support it.
8. Chain of custody is not paperwork; it is the story of the evidence.
9. Treat every sample as if it could become the most important evidence in the case.
10. Your report should be understandable to someone who wasn’t in the laboratory.
11. Never confuse “consistent with” with “identified as.”
12. Independence is more important than pleasing the investigator, prosecutor, or defence.
13. Question your own findings before someone else does.
14. Contamination prevention starts before you touch the evidence.
15. If something goes wrong, report it—hiding an error can turn a mistake into misconduct.
16. Good forensic science should survive cross-examination.
17. The evidence does not belong to you; you are responsible for it.
18. Stay curious. A forensic scientist who stops learning eventually starts relying on outdated science.
19. Never forget that behind every exhibit number is a real person and a real case.
20. Your duty is to the evidence, not to the outcome.

The bottom line

Forensic science is ultimately built on trust. Every report, examination, and testimony carries responsibility because behind every exhibit number is a real case and real people.