I am so sorry to hear that you are having to go through this difficult situation.  It seems as though you have an excellent student and some of his kidding was taking too seriously.  There is just so much bullying and terrible things that has happened in school, that a harmless joke is considered to be a dangerous situation.  Some of it is over reacting drama, but the school can not afford to take that chance if a student makes a threatening comment, they must investigate it to prevent harm to the other students.  Most likely you are just experiencing the "red tape" of the investigation of his joke and you will be able to reconcile this situation at the meeting.  

Remain calm and supportive of your son and if possible I would have him attend the meeting also to express his regrets for the joke and apologize for having offended others.  This would also provide the opportunity for you to discuss his frustrations with the bullying of the other students and express that they too need to have a meeting to consider what actions should be taken to cease that behavior.  This may be a blessing in disguise and instead of causing problems for your son, just may be what is needed to end some of his concerns or worries.

I wish you both the best and you should not allow yourself to be intimidated by this meeting.  I believe that you can handle this with ease and remember that you are only meeting with other people that is on the same team with you to work together and decide what is in the best interest of your child as well as the other students.  Best Wishes!!!

well i would ask him to stop

well i think your kid needs to apoligse and tell everyone that the statment was not ment to make anyone feel unsafe.If this don't work then you might have to get your son to switch schools or tell the principle that your son is very sorry for what he did.He could write an apoligie letter to all the kids and say sorry and that he was not trying to scare anyone.

let the school board have it, the school board officals are only trying to cover their rear ends so if something were to happen they could say they looked into it. As far as im concered the administration needs to be looking into the bullying instead of bothering a kid who was messing around with his friends, at his own house.