Yahya Abd-al-Latif Ayyash (Arabic: يحيى عياش, February 22nd 1966 – 5 January 1996) was the chief bombmaker of Hamas and the leader of the West Bank battalion of the Izz ad-Din al-Qassam Brigades. In that capacity, he earned the nickname the Engineer (Arabic: ‎المهندس, transliterated Al-Muhandis).

Ayyash is credited with advancing the technique of suicide bombing in the Israeli-Palestinian conflict. The bombings he orchestrated caused the deaths of approximately 90 Israelis. A master of disguise, Ayyash was the most wanted man in Israel for three years, and the target of a massive manhunt. Ayyash was assassinated by Israel's Shin Bet in 1996. Shin Bet tricked a trusted friend of Ayyash's into giving him a bomb-laden cell phone. When Ayyash used it, Shin Bet detonated it, killing him instantly.

To Palestinians, he is a celebrated hero who has streets and other locales named in his honor.

Ayyash was born in Rafat, the eldest of three brothers. As a child, he was very pious, receiving an award from the Islamic Trust for his talent in memorizing the Koran. While a boy, Ayyash showed a talent for electrical and mechanical work—repairing radios, television sets, and the like. After graduating from high school in 1985, he entered Bir Zeit University in 1987. He received a bachelor of science in electrical engineering in 1991.

Robert "Bob" Booker Baer (born July 1, 1952) is an American author and a former CIA case officer who was primarily assigned to the Middle East. He is currently TIME.com's intelligence columnist and has contributed to Vanity Fair, The Wall Street Journal, and The Washington Post. Baer is a frequent commentator and author about issues related to international relations, espionage and U.S. foreign policy.

Baer was born in Los Angeles, raised in Aspen, Colorado, and aspired to become a professional skier. He spent many years of his childhood with his mother in Europe before returning to the US. After a fairly poor academic performance during his freshman year at high school, his mother sent him to Indiana's Culver Military Academy. In 1976, after graduating from the Georgetown University School of Foreign Service and entering the University of California, Berkeley, Baer decided to join the CIA's Directorate of Operations (now the National Clandestine Service) as a case officer. Upon admittance to the CIA, Baer engaged in a year's training, which included a four-month paramilitary course and foreign language courses.