Security sources say unidentified gunmen shot and killed Libya's military police force commander as he left a house in the eastern city of Benghazi on October 18.
The sources said that several bullets hit Ahmed al-Barghathi, who died later in hospital.
Benghazi, the cradle of the 2011 uprising that ousted dictator Muammar Qaddafi, has seen a series of assassinations targeting members of the security services.
The shooting of Barghathi, who was on vacation in the city, is the highest-profile attack there for weeks.
Last year, U.S. Ambassador Chris Stevens was killed during a suspected Islamist attack on a U.S. diplomatic mission in the city.
Much of Benghazi is under the control of former rebel groups who officially are helping the government maintain security but are themselves often a source of violence.
Based on reporting by Reuters and AFP