AIBU to search DS room

[aliveandhealthy]

I overheard DS16 speaking about magic mushrooms whilst on the phone with his friend. Based on the conversation I have reason to believe he may be in possession or is going to be in possession of magic mushrooms. I haven't confronted him about what I heard yet as I'm not sure how to approach this situation. If this was anything else, I would've pretended not to have heard the conversation and minded my business, yet this is drugs we're talked about.

AIBU to consider searching his room? How would you approach this situation? I am considering having a serious, calm, conversation about the dangers of drugs.

Personally I would sit down and talk to him about it. Calmly if you can. I know its not easy.

I probably would search it. Usually I'm very much a keep out of their private space sort of person but this is different. Magic mushrooms can have serious effects. They might be ordinary cooking mushrooms and he might have been scammed. Then again they could be poisonous.
It might just be bravado on the phone but no point discussing it with him until you have evidence.