As someone who is 18 years old I do not feel it is right to suggest 18 year old's are at the same level of maturity compared to other adults. Throughout much of Erik's cross examination the prosecutor (Kuriyama) kept putting emphasis on the fact that Erik was 18 years old during the time of the killings. There were also several suggestions that Erik was "old enough" to reject his Father's advances and I feel that was very unfair for prosecution to imply. All things considered, both Erik and Lyle were heavily dependent on their father and not only did their father have control over their present but their future as well. This is the same man that had been sexually abusing Erik since he was SIX years old. I hate that fact that the prosecution chose to not understand the weight of the abuse. It is not at all surprising to me that Erik felt helpless in that situation. I did not wake up the next day on my 18th birthday feeling like a completely new person nor was I ready for adulthood. I can't necessarily speak for Erik but I don't think he was at a high level of emotional maturity. Many people talk about how the brothers shouldn't be infantilized while simultaneously treating them as if they were older.