Backing Knife

What should you do with the bloody knife?

If you are walking down the street one night and some guy comes up to you with a knife and tells you to give him your wallet and you do then he says thanks (bad word) and turns to run away and you tackle him take your wallet back and his knife and stab him in the back of the thigh then let him go what should you do with his bloody knife?

You should (hypothetically) have finished him off and anyone else who saw the event. No witnesses. Hypothetically of course. Then to get rid of the knife you should lick off all the hypothetical blood and dance naked around a hypothetical fire and throw the knife in the flames.

Hypothetically

Shonen Knife 少年ナイフ: “Banana Chips” @ Annandale Hotel 25-Sep-09