I (and probable along with many others) watched the movie "Being Charlie" after hearing about the Reiners being murdered. I've lived a sheltered life and have never experienced having to live around someone with a drug problem except maybe alcohol. The movie was supposed to be semi-autobiographical. If the Reiners son Nick did kill his parents (and it's not official I don't think, but it's looking that way), it's incomprehensible.
The movie and what little I've read about the Reiners dealing with their son's drug problem, is that they seconded guess their decision in getting him into rehab and into all of these sobriety centers. They were thinking maybe having him talking with counselors and these people with diplomas hanging on the walls wasn't maybe the way to go.
Not being a parent, I obviously don't know the answer to getting someone addicted to drugs help, but I don't think any parent does. All they can do is what they think is best, and I'm sure that's what Reiners probably did. I loved Rob Reiners works as an actor ever since he was in "All In The Family". He was a phenomenal director. I feel so bad for the Reiners family. May the Reiners R.I .P..
As a side note, I remember Carrol O'Conner's son having drug problems. Mr. O'Conner finally caught up with his dealer, and I'm pretty sure he did time. Fortunately, his son (Hugh O'Conner) did not kill his parents. Unfortunately, he did commit suicide.