In 1989, he told David Frost:
"My only connection with Robert Kennedy was his sole support of Israel and his deliberate attempt to send those 50 bombers to Israel to obviously do harm to the Palestinians". Some scholars believe the assassination was one of the first major incidents of political violence in the United States stemming from the Arab–Israeli conflict in the Middle East. The interpretation that he was mostly motivated by Middle Eastern politics has been criticized as an oversimplification that ignores Sirhan's deeper psychological problems. During his trial, Sirhan's lawyers attempted to use a defense of diminished responsibility, while their client tried to confess to the crime and change his plea to guilty on several occasions. Sirhan testified that he had killed Kennedy "with 20 years of malice aforethought". The judge did not accept this confession and it was later withdrawn.