Ohhhh, that is a hard one. From my experience when good kids make bad choices, they are trying to get their parents attention. Albeit, I am sure not always. Sometimes we get so wrapped up in life that we only think we are giving our kids all the attention that they need. I would frimly but lovingly discipline him and try to spend a little bit more alone time with him. Just talking or playing a game. I would also check out who his friends are, b/c at this age they are very influenced by the group they are hanging out with. Good Luck

Oh.. That is a bit hard for you.  I think in these situations, you should opt to listen and have some chat time to him involving his schools, friends and other interests he might want to share to you.  They badly need attention and needs a lot of social communication.  In these you may find a lot of things he might just spill in any moment that may surprisingly be a simple bonding for both of you.  Never loosen up your patience.  Be loving and stay happy at home with his' company.  

Well yes he made the bad decision but to keep that from hapening again check his back pack everyday and tell him to never ever do that again but in your nicest voice

Remind yourself, we are all human and make mistakes.  Mistakes happen.  The important thing is that your son acknowledges that what he did was wrong and feels remorse about it.  This is extremely important.  He NOW needs to make the right decision.  This could be apologizing to the school, giving a talk to other kids about making wrong decisions, etc.  Talk to him about this.  Explain that he is a good person who made a mistake.  Now, what can we do to make this better in your eyes and in his eyes.

i'm in the same boat. my son found his dads pocket knife at the end of our driveway on the way to the bus stop and grabbed it as he was running late for the bus. he knows that my husband has to turn it in every so often for a new one or we get charged and financially we can't afford it, so my son was just going to keep it put away and bring it home, he didnt see a problem, then he best friend saw the tip of the handle sticking out and asked what it was and my son said nothing, so his friend started chasing him in circles til he got hold of the tip of it and then the opened it up. he waved it in the air so alot of kids started to gather and then the noon duty aide saw so the boy threw it back at my son so he wouldnt get in trouble. my son closed it and ran for the bathroom and wouldnt come out but the NDA went in andgrabbed him around the waist and my son grabbed the door or something similar and theman carrying him ended up smashing his hands. my son just turned 10 is a straight a student,perfect attendance,volunteers for everything,etc, everyone likes him and has never been in trouble. the principal didnt bother to call me til 3 1/2 hours after it happened and the sheriff was there and they had already decided to suspend him for 5 days pending the hearing to see if he is to be expelled.There are schools where kids threaten to kill other kids and in Ca. thats considered a terrorist threat and you goto jail. My son has never done anything wrong and the school he is at i have put him and my 8 yr old there the last 2 years and they hate it. the school they were in before i would have to drive them to cause the buses dont go there, but i had to change them as i have partial seizure disorder which was under control and then out of no where it came back, but this january i will bill seizure free long enough to get  my license back and get my boys out of that hell hole as that school has done nothing but cause both of them anguish and they used to love school which is only 4 miles from our home.maybe have your son write a letter as to why he took the toy gun to school, my son did that w/o me even telling him to as he wanted to read it to the panel and not leave anything out. i feel your stress as i havent slept and keep wondering what did i do wrong? all we can do is the best we can. good luck!

As you said he is a good kid and made one wrong decision - has he written to the school to apologise and admit that he made a mistake?
He will be well aware of the strain he is putting you under and this is one awful way to learn a lesson.
Hopefully the school will accept that this was one BIG mistake and take him back - they will have one well behaved pupil afterwards.