I have two about that age. . .one 14 and one 12. I think it might be considered somewhat normal behavior. They do seem to have an "angry" stage, but your concern seems to indicate you think it might be just a bit more going on, therefore I would just pay close attention to what is going on with him.

They seem to go through a period of pushing the limits. . .they are changing and may be uncomfortable with it and therefore act out because they don't know how else to deal with it.

You did right to send him to his room and your DH did right in "enforcing" your decision. Hurting others in the family isn't something you can overlook. Thats where DH's sometimes have to step in and deal with it and mom has to let them. The more they get by with it, the further they push next time. If they know there are consequences, they may think twice.

You are probably well aware of the warning signs of drug use. . .sudden change in behavior, belligerence, change of friends, etc. Pay close attention to what is going on with him.

You also might try to find out if something is going on at school. . .kids making fun, running with a bad crowd, anything out of the ordinary.

I find that my kids will spill the beans a bit easier if I talk to them alone, non accusatory, not pushy (the more you try to pick them, the more they clam up), etc. Also, if I go in about bedtime and sit and talk for a minute with the lights out it seems to loosen their tongues a bit. Simply say something like "I'm not fussing at you, but I'm wondering what were you so angry about earlier? Can you tell me?" Sometimes it works like this in a car also. . .where they can talk without having to look you in the eye.

I know some will disagree with me, but if you suspect drugs, I would not hesitate to prowl my child's room to find out. There are no "rights" as far as I'm concerned when it comes to something as detrimental to my child as drugs.