It is horrible that this has happened. I am sure that you are going through this because you have a son that same age and can empathize with the parents. You probably feel your own child's grief as well.
I'm sure if this young man was planning to commit suicide though, if he didn't use a gun, he could have used a number of other things, including medicines right in the home too.
I hope that you can cope well with this. I know what you mean about counseling though, but you may end up wanting to take that road.
I pray for peace for you, your son and the boy's family.