Faisal bin Musaid Al Saud

Beirut newspapers offered three different explanations for the attack. An-Nahar reported that the attack may have been possible vengeance for the dethroning of King Saud, because Faisal was scheduled to marry Saud's daughter, Princess Sita, in the same week. An-Nahar also reported that King Faisal had ignored his repeated complaints that his $3,500 monthly allowance ($16,700/month in 2020 dollars, $200,500/year) was insufficient and this may have prompted the assassination. Al Bayrak reported that according to reliable Saudi sources, King Faisal prohibited him from leaving the country because of his excessive consumption of alcohol and other drugs and the attack may have been a retaliation against the ban.

On 25 March 1975, Prince Faisal went to the Royal Palace in Riyadh, where King Faisal was holding a meeting, known as a majlis. He joined a Kuwaiti delegation and lined up to meet the king. The king recognized his nephew and bent his head forward, so that the younger Faisal could kiss the king's head in a sign of respect. The prince took out a revolver from his robe and shot the King twice in the head. His third shot missed and he threw the gun away. King Faisal fell to the floor. Bodyguards with swords and submachine guns arrested the prince. The king was quickly rushed to a hospital but doctors were unable to save him. Saudi television crews captured the entire assassination on camera.

In 1971, he received a bachelor's degree in political science from the University of Colorado and then returned to the San Francisco Bay area. At the University of California at Berkeley, he enrolled in graduate courses in political science, but did not receive a master's degree.

In 1969, while in Boulder, he was arrested for conspiring to sell LSD. He pleaded guilty and was placed on probation for one year. In May 1970, the district attorney dropped the charges.

Faisal arrived in the United States in 1966 and attended San Francisco State College for two semesters studying English. Allis Bens, director of the American Language Institute at San Francisco State, said, "He was friendly and polite and very well brought up, it seemed to me." While Faisal was at San Francisco State, his brother Khaled was killed. After leaving San Francisco State College, Faisal went to the University of California at Berkeley and then to the University of Colorado at Boulder. He was described by his peers as "[a] quiet, likable, notably unstudious young man". University of Colorado Professor Edward Rozek, who had taught him in three comparative government courses, described him as "academically a D and a C student".

In 1965, Faisal's older brother Khaled was shot and killed by a Saudi police officer while he led an assault on a new television station in Riyadh that had been recently founded by King Faisal. Some people opposed the establishment of a national television service, as they believed it immoral to produce images of humans. While that is the official version, the details of his death are disputed and some reports allege that he actually died resisting arrest outside his own home. Regardless, no investigation over his death was ever initiated. Faisal had two other full siblings, Prince Bandar and Princess Al Jawhara. Saudi businessman Abdul Rahman bin Musa'id Al Saud is his half-brother.

Faisal bin Musaid Al Saud (Arabic: فيصل بن مساعد آل سعود, Fayṣal bin Musāʿid ʾĀl Suʿūd; 4 April 1944 – 18 June 1975) was the assassin and nephew of King Faisal of Saudi Arabia.

Faisal bin Musa'id was born in 1944. His father was Prince Musa'id bin Abdulaziz, son of the founder of Saudi Arabia and half-brother to all the six Saudi kings, including King Faisal, who have succeeded the founder. Faisal bin Musa'id's mother was Watfa, a daughter of Muhammad bin Talāl, the 12th and last Rashidi emir. Musa'id and Wafta were divorced when Faisal was still young. Therefore, he and his siblings were much closer to their maternal Rashidi relatives than to their paternal Al Saud relatives.