Adnan al - Ghoul Adnan Al - Ghoul ( c . 1962 – 21 October 2004 ) ( ) was the assistant of Mohammed Deif , the leader of the Izz ad - Din al - Qassam Brigades , the armed wing of Hamas . He was killed in a targeted killing along with Imad Abbas when an Israeli Air Force Apache helicopter fired missiles at their car in Gaza on 21 October 2004 . By Hamas members he is seen as a martyr . Adnan Al - Ghoul was one of the senior operatives in Hamas ' military - terrorist apparatus . He specialized in explosives and among other attacks was behind the 1995 terrorist attack at the Beit Lid junction in central Israel , and the 1996 bombing at Dizengoff Center in the heart of Tel Aviv , together responsible for the deaths of 32 Israelis . Adnan was not an " ordinary rank - and - file " terrorist operative but rather a top - ranking terrorist of Hamas ' military - terrorist apparatus in the Gaza Strip . He specialized in the preparation of IEDs and developed the Qassam rocket system for Hamas ( earning him the nickname " father of the Qassam " ) . He was the right - hand man of Muhammad Deif , head of Hamas ' military - terrorist wing , and had an important role in Hamas ' plot to sabotage the Oslo Accords . For example , Al - Ghoul was involved in manufacturing the bombs used in t he double attack at the Beit Lid junction in the center of Israel on 22 January , 1995 , in which 22 Israelis were killed . He also prepared the explosive belt for the 1996 Purim suicide bombing at Dizengoff Center in the heart of Tel Aviv , in which ten Israeli civilians were killed . He died in an Israeli Air Force targeted killing on 21 October 2004 . Identified by the Israeli Defense Forces ( IDF ) as Hamas ' top bombmaker , he joined the organisation soon after its creation in 1988 . He then served as an assistant to Izz ad - Din al - Qassam Brigades ' s top engineer , Yahya Ayyash . Al - Ghoul took over Ayyash ' s role in 1996 , after his mentor ' s targeted killing . Early in the Al - Aqsa intifada , Al - Ghoul developed the Qassam rocket . Al - Ghoul also masterminded the development of weapons made from raw material and equipment smuggled into the Gaza Strip using tunnels in Rafah , on the border with Egypt . Among those weapons , anti - tank rockets such as the Al - Bana , the Batar , and later the Yasin were often used by Hamas in its attacks against settlements or Israeli soldiers in Gaza , as well as for defense purposes during IDF ' s incursions . Al - Ghoul lived in hiding and never spoke to the media . Pictures of the 46 - year - old father of four were released by Hamas only after his death . On 26 September 2003 , he reportedly attended a meeting with Mohammed Deif , Ismail Haniya , one of Hamas ' political leaders , and the organisation ' s spiritual leader , Sheik Ahmed Yasin , when Israeli forces bombed the house where they gathered . Al - Ghoul ' s eldest son Bilal was killed in a 2001 air strike in Gaza , and his second son Mohammed was killed the following year along with a cousin during a botched raid in the family home in Maghazi , south of Gaza City . Although the Izz ad - Din al - Qassam Brigades , for security reasons , withheld at the time the identities of the engineers that were involved with Al - Ghoul in overseeing the production of weapons for the group , it was disclosed in March 2006 that Abdel Mo ' ti Abu Daf was , along with imad Abbas , Al - Ghoul ' s top assistant . Daf died on 26 February 2006 after a grenade accidentally detonated during a training .