I think in the moment you can't be sure how you'll respond. Whether it was them killing someone "justifiably" or killing someone because he (your son) couldn't handle his emotions, killed some chick ex, or killed the chick, etc.. at the end of the day its YOUR SON and that would weigh heavily on whatever you think...
And for full disclosure, for any nikka in here that doesn't have kids or nikkaz who have babies... let me make this clear, whether they're small or grown THEY WILL LIE to you. So don't expect their story to be 100% true. Maybe 40% if you're lucky.
So all this shyt about "my son will be a man of integrity and a beacon of honesty and compassion" ..yea good luck with that