I lost my only brother 5 years ago due to alcohol use. Although it is not the same as loosing a son to a madman, I can tell you from my perspective that you did the right thing. When my brother died it was quite unexpected. We all knew he had a problem with alcohol. We all tried to get him to stop. Ironically he did stop but, apparently the damage had already been done. He had been clean and sober for 6 months, we were planning our first ever hunting trip together (we had both been hunting for years just never went together for various reasons) the weekend before our trip he called and said he couldn't make it do to a big project at work. A week later I was sitting beside his hospital bed watching him die. The doctors said there was nothing they could do.
What makes me tell you that is this. After the funeral some of his friends wanted to get together and say goodbye. They all asked me to go, saying they wanted to have a drink in his memory. I told them I would never let another drop of alcohol touch my lips. Even now, years later, I run into his old buddies and they want to get together and have a beer. I still say no. I know that nobody that makes alcohol forced my brother to drink. I know it was my brothers choice to open that bottle. I know my not drinking will not bring him back. I still won't have anything to do with alcohol.
As for when to talk to him, just be his friend, he will let you know when he is ready to talk. He may not come out and say it but he needs his space, he need time to grieve, he needs time to be mad, he needs time to force himself to go on. Whoever said time heals all wounds is full of it. I still break down when I think of my brother (the keyboard I am typing on is very blurry right now) All time does is let you learn how to force yourself to think about something else. In time he will mention his son. He will make some passing comment and you can be ready with a comment that might help him realize his son might still be here if he had been armed. When I hear people talking about the shootings at schools and how all those kids would be alive if the were no guns or stricter gun laws, I just remind them that Timothy McVeigh killed over 100 innocent men women and children without firing a single shot. It's not the gun, it's the person holding the gun.
Don't push him, a person who is grieving can go from happy to sad to down right pissed off very quickly. I got rid of a lot of old friends because they kept pushing, handing me a beer, asking why I don't drink, telling me it's not the alcohol, or worst of all... telling me what my brother would have said or done. They had known him for a few years and were going to tell me, his only brother, what he would have said or done.
