The attack was carried out by Habib Shartouni and allegedly planned by Nabil Alam, both members of the Syrian Social Nationalist Party (SSNP).

Gemayel had planned to use the IDF to push the Syrian Army out of Lebanon and then use his relations with the Americans to pressure the Israelis into withdrawing from Lebanese territory.

][8] Habib Tanious Shartouni, a Maronite Christian, was born in a small village called Chartoun (Arabic: شرتون) in Aley, Mount Lebanon.

[9] Shartouni fled to France where he attended a university in Paris and obtained a degree in business until the late summer of 1977 during which he officially joined the SSNP upon his first visit to Lebanon and became an active member ever since.

[12] Gemayel's body was finally identified five and a half hours after the explosion by a Mossad agent in a church near the site, where the dead were being collected.

[13] Then–prime minister Shafik Wazzan confirmed the following morning that Gemayel had indeed been killed in the attack,[14] saying, "I face this shocking news with the strongest denunciation for this criminal act.

In a separate conversation, Sharon and Eitan agreed that the Israel Defense Forces (IDF) should not enter the Palestinian refugee camps in Beirut, but that the Phalange should be used instead.

American President Ronald Reagan, who had been one of Gemayel's staunchest supporters, issued a statement of condolences for his death, saying "this promising young leader had brought the light of hope to Lebanon.

Habib Shartouni was held for eight years in Roumieh prison without an official trial, before escaping during the final Syrian offensive that marked the end of the Lebanese Civil War.

[26] On 20 October, the Judicial Council, Lebanon's highest state security court, sentenced Shartouni and Nabil Alam to death in absentia and stripped them of their civil rights.