Police Quest are a series of police simulation video games produced and published by Sierra On-Line between 1987 and 1998. The first five were adventure simulation games, the first three of which were designed by former police officer Jim Walls. The fourth and later titles were designed by former LAPD Chief Daryl F. Gates. Both SWAT and the real-time strategy game SWAT 2 still carried the Police Quest name and were numbered V and VI in the series, respectively, although subsequent titles in the series would drop the Police Quest title altogether.