Rule #1: Never let suspects sit together.
Other Rule #1: Never screw over your partner.
Rule #2: Always wear gloves at a crime scene.
Rule #3: Never believe what you are told. Double-check.
Other Rule #3: Never be unreachable.
Rule #4: Best way to keep a secret: Keep it to yourself. Second best: Tell one other person—if you must. There is no third best.
Rule #5: You don’t waste good.
Rule #6: Never say you’re sorry.
Rule #7: Always be specific when you lie.
Rule #8: Never take anything for granted.
Rule #9: Never go anywhere without a knife.
Rule #10: Never get involved personally on a case.
Rule #11: When the job is done, walk away.
Rule #12: Never date a coworker.
Rule #13: Never involve lawyers.
Rule #14: Bend the line, don’t break it.
Rule #15: Always work as a team.
Rule #16: If someone thinks he has the upper hand, break it.
Rule #18: It’s better to seek forgiveness than ask permission.
Rule #20: Always look under.
Rule #22: Never, ever bother Gibbs in interrogation.
Rule #23: Never mess with a Marine’s coffee if you want to live.
Rule #27: Two ways to follow someone. First way, they never notice you. Second way, they only notice you.
Rule #28: When you need help, ask.
Rule #35: Always watch the watchers.
Rule #36: If it feels like you’re being played, you probably are.
Rule #38: Your case, you’re lead.
Rule #39: There is no such thing as a coincidence.
Rule #40: If it seems like someone’s out to get you, they are.
Rule #42: Never accept an apology from somebody who just sucker punched you.
Rule #44: First things first, hide the women and children.
Rule #45: Left a mess I gotta clean up.
Rule #51: Sometimes you’re wrong.
Rule #62: Always give people space when they get off an elevator.
Rule #69: Never trust a woman who doesn’t trust her man.
Rule #91: When you decide to walk away, never look back.
NCIS, Mondays, 9/8c, CBS
This article originally ran on tvinsider.com.