In this case of the murder of Robert Kennedy, it was Arabic extremism that leads Sirhan to act so wrongly, He was against American support of Israel.
His motive has been considered not credible.
Firstly he was raised Christian. He is rumored to have connections with the CIA...and he hasnt clarified yet how he knew RFK would go through the kitchens. Who told him.
Since he won't tell us who told him, who his accomplices are, he deserves no parole.
Those people are surely dead...by now...so he is loyal to his cause.