How To Use CSI Techniques To Find Out Who Used Your Coffee Mug

Step 1: You will need

Step 2: Dust And Discover

Brush makeup powder around the rim of the coffee mug. Gently brush away powder that doesn't stick to the surface. You should see at least one lower-lip mark.

Step 3: Collect The Evidence

Carefully place transparent tape over the lower-lip mark. Put the tape on the piece of paper. You now have the smoking gun.

Step 4: Set The Trap

Tell female suspects you got new lipstick, but you think it's the wrong color on you. Ask them to try the lipstick. Make sure they put plenty on. For your male suspects,
use a similar tactic. Mention you shouldn't be eating sweets in the office, and
offer your slightly-melted candy bar.

Step 5: Seize The Sample

Suggest they use the envelope you just happen to have. The crease in the envelope will prevent them from paper-cutting their lips. Blot it. When they've created your sample, offer to get rid of it for them, then head straight to the lab.

Step 6: Patterns

The five most common lip patterns studied in forensic scientist are
"short vertical grooves, long vertical grooves, diamond grooves, rectangular grooves and branching grooves."
Your job is to find which lip pattern your new evidence falls under, and match that pattern to the criminal. Put your lip evidence from the coffee mug next to your samples. Compare each sample to your evidence.