As for the idea of charging the parents of shooters, it's a bit of a stretch, I think. But in this case, they were negligent, and gave him a gun. There are a whole lot of people who should not be parents, yet are having kids because they think it's the way it's supposed to be.
I'm not sure it's ever really been much different. Bad parents have been around for a long time. The problem is that the people filling in now as parents- school counselors, therapists, and the LGBTQ crowd are doing tremendous harm.
they DIDNT GIVE HIM THE GUN...the weapon was bought to target practice at a gun range, with the understanding it would be his when he turned 21. The gun was locked up the day of the shooting, and the kid unlocked it. This sets a dangerous precedent, you could apply this to every crime committed..”you didnt raise him right, so youre guilty too”....ill be shocked if they get a conviction, but the defense attorney is awful...she couldnt get these people out of jail almost 3 years later...ridiculous.