Legal Question in Criminal Law in California

Without knowing what the terms of the plea bargain were, we can not give a good answer to your question. It is possible, unless your son had the gun/weapon because he worked in a dangerous neighborhood, etc., that the judge will reinstate the original charge since your son less than 6 months after being told to obey the law broke it [he was not arrested the first time he carried the weapon and must have done something to cause the policeman to search him for a weapon]. If both are felonies, he will have two strikes against him. He better get a public defender or private attorney as he may be facing jail time.

In addition to whatever penalty and punishment the new charge brings, he violated probation on the original charge, which can be revoked and he can be put in jail on the original sentence.