Assassin came from Arabic hashshashin, "hashish-users", a name of an Islamic order founded about 1090, whose members were said to take hashish before being sent forth to assassinate leading Crusaders.
The police were able to catch Sidney's assailant. Enrique Wade was already wanted by the police because he was a suspected assassin of another person who was in the same park where Sidney was attacked.
2. Someone who murders by surprise attack; especially, a person who carries out a plot to kill a prominent person.
3. A member of a secret order of Muslim fanatics (founded in the 12th century), active in Persia and Syria from about 1090 to 1272, whose primary object was to assassinate, terrorize, and to kill Christian Crusaders.
4. Etymology: in Anglo-Latin from about the mid 13th century, via French and Italian, from Arabic hashsashin, "hashish-users", a plural of hashshash, Arabic for "hashish-eater".
In English, the Arabic plural form was thought to be a singular form which became known as a fanatical Ismaili Muslim sect at the time of the Crusades known to murder opposing leaders after intoxicating themselves by eating or smoking hashish or the drug cannabis.