Majid Nassar was a terrorist and the leader of the terrorist group Al-Sakar.
He initially claimed responsibility for the attack on the Capitol, but during his interrogation between him and the FBI, he revealed he did not actually commit the act, but claimed responsibility to divert attention away from the actual conspirators. Shortly after, Catalan poisoned his meal and Majid was killed. Jason Atwood was later framed for the murder of Nassar.
Six years before the events of the series, Majid's family was hit by U.S missiles outside Barmal. He searched for a week to find his family's remains, but to no avail. Some time later, he would later go on to lead the terrorist group Al-Sakar. However, he and the latter simply latched on to bigger groups and claimed responsibility for a nightclub bombing they did not commit.
After the Capitol bombing, Majid sent a video to the U.S government claiming responsibility for the attack. The Algerian government kept Nassar out of U.S custody and thus prompted the U.S Navy SEALs to apprehend him. When he was discovered in the basement an Algerian hospital, they found Nassar holding a number of children hostage. They managed to capture the terrorist leader, but at the cost of a fellow SEAL.
He was later brought to FBI agents Hannah Wells and Jason Atwood, who were both unconvinced that Majid actually bombed the Capitol and wanted to learn who set him up. Hannah taunted Nassar that he and Al-Sakar just latched on to bigger groups and that they could never carry out something as complex as the Capitol bombing. Majid denies this and tells that only they could carry the kind of explosives used in the attack in large amounts. However, after Hannah threatens his other family, Nassar confesses that the person who set him up was a person named Catalan and that he only went along because they both wanted "death to America".
Not long after, Majid Nassar was found dead in his cell from food poisoning caused by Catalan, who put thallium into his food.