• #1 Never let suspects stay together./Never screw (over) your partner.
• #2 Always wear gloves at a crime scene.
• #3 Don't believe what you're told. Double check./Never be unreachable.
• #4 If you have a secret, the best thing is to keep it to yourself. The second-best is to tell one other person if you must. There is no third best.
• #6 Never say you're sorry. It's a sign of weakness.
• #7 Always be specific when you lie.
• #8 Never take anything for granted.
• #9 Never go anywhere without a knife.
• #10 Never get personally involved in a case.
• #11 When the job is done, walk away.
• #12 Never date a coworker.
• #13 Never, ever involve lawyers.
• #15 Always work as a team.
• #18 It's better to ask forgiveness than ask permission.
• #22 Never, ever interrupt Gibbs in interrogation.
• #23 Never mess with a Marine's coffee if you want to live.
• #27 There are two ways to follow.

1st way - they never notice you;2nd way - they only notice you.

• #38 Your case, your lead.
• #39 There is no such thing as coincidence.
• #40 If it seems like someone's out to get you, they are.
• #44 First things first, hide the women and children.
• #45 Clean up your messes.
• #51 Sometimes - you're wrong.