He used the toothbrush. I don't know if the fingerprint is clear.
My processing of the evidence would not hold up in the Western world in a court.
"How can you provide the police in Cambodia with proof it was a the scene of the crime?"
Surveillance camera at my hotel shows him with a face mask, can't recognize his face.
As far as I know, for ID cards in Cambodia, fingerprints are taken. If I can get a clear fingerprint off the toothbrush, and get the to the right government office in Cambodia, he will be found.
As for value for money, the guy is a serial thief, I know two other victims. The stolen object was a mobile phone, worth about 500 USD (when I buy the same model second hand). For me, it's a matter of principle, the thief will continue until someone catches him. I have the time and money to try to be the one.