the lawyers didn't guide the extended family and friends to say they'd witnessed occaions where the bys were taken innto a room with the father for extended period... nor did the lawyers teach the family to say that the boys came to them when they were just youngsters complaining about their father's behaviour..
Why did the Menendez brothers kill their parents?
Motive has long been at the heart of this case.
During their trials, prosecutors painted the brothers as spoiled rich kids who killed their wealthy parents in their Beverly Hills mansion so they could access a $14m (£10.7m) fortune.
They argued the duo methodically bought shotguns and fatally shot their parents a total of 13 times as the couple watched TV. They then went gambling, to parties and on shopping sprees, buying things like Rolex watches.
Who is the Menendez family, at centre of US murder case?
It was ultimately a confession to a psychologist that helped lead to their arrest when the girlfriend of their doctor reported it to authorities.
The brothers ultimately admitted to the killings - but argued they acted out of self-defence after years of emotional, physical and sexual abuse.
They told the court they feared their parents would kill them if they didn’t act first. Lyle and Erik testified they confronted their parents about the sexual abuse and things had become combative in their household and they believed their parents were planning to kill them.
Family members testified about the abuse they witnessed - but none said they saw sexual abuse first-hand.
Menendez brothers: Three possible paths to freedom
From the documentary the family testified that the father was mean And belittled them.