What will happen if my son is caught with marijuana?

You should not call the police, that would only make matters worse. You can get him into a drug counseling program or NA meeting if you do not have insurance. You must keep him from smoking cigarettes as that is a totally foolish decision. As gar as smoking pot, it is better than using hard drugs or alcohol and not as dangerous as cigarettes. You cannot make him stop, you can explain to him that he should not smoke it or carry it in public, sell it, give it away (same as a sale), or bring it to school.

If you call the police you could be placing your child in the hands of the criminal justice system. This is almost never a good idea. Possession of marijuana carries a maximum penalty of one year in jail. Speak with psychological professionals about counseling and treatment programs.

If you want the state to control your life, brand you as a bad parent, torture your teenager for something as silly as smoking marijuana, then go ahead. If you want to start being a parent, you will end up with a happier ending.

Take him to substance abuse counseling, tell the other child's parents and ban him form seeing those people. That is what you should do.

As the father of a teenage boy myself I know how challenging that age can be. Most kids don't want to listen to their parents, and many people I know in similar situations have sought out a good counselor or psychologist specializing in teen issues, who has been able to mediate the situation, or give direction to a young person who is struggling to find his/her way. I would not go to the police, however, not at this point. If things get worse, indications of more serious drug usage or other bad behavior like stealing, cutting school and the like, you might consider it but you shouldn't do it before discussion this with an attorney first. The consequences of a criminal record, even a juvenile one, are more vast that you might imagine, much more so that simply a conviction for a minor drug offense. So that is the last option you should consider.

Do not call the police, call his dad, brother and an attorney to explain to him what he is about to do with his life, potentially ruining it.

I can't advise you on how to deal with your child, but I can tell you that involving the police is not the way to go. In MA, possession of anything under 1 ounce of marijuana is no longer a criminal issue. It is a civil penalty. However, the police have a way of taking that information and ascribing it to your son for future reference. In other words, they will probably issue him a civil violation for possession of under an ounce of marijuana. However, they will also have him marked as a kid who uses pot. They will not do anything at the moment with this, but it will from that point on be the way they look at your child, as a drug user. It would be far better to have another professional speak with your son. You may consider counseling or perhaps a family friend who is a lawyer or a doctor or someone in authority that your son trusts, that you can trust not to use the information against him (you cannot trust the police in that regard).