In addition to the files of Sonny Bonds and other police officers, the "Personnel" directory of the station computer includes files of Jim Walls and other Sierra employees who took part in creating the game.
When looking at the bulletin board in the homicide room, sometimes appears the message: "Herein lies the names of the programmers who without undo fanfare brought you this game. Doug Oldfield, Chris Hoyt, Kim Bowdish and Mike Larsen".
On day 6, Sonny distracts the janitor by tossing a roll of toilet paper into the toilet, making it overflow. While the janitor removes it, he comments: "Bet it was that Officer Walls again" - presumably referring to Jim Walls.
Sonny plants a tracking device on a suspect's car in order to pursue him. Although this was pretty much legal back in 1991, with the advent of GPS technology in the 21st century, police now need to execute a search warrant prior to using tracking devices on vehicles (see: United States v. Jones, 132 S. Ct. 945 (2012)).
The trivia item below may give away important plot points.
According to The Police Quest Casebook, Officer Pat Morales is the half-sister of Jessie and Michael Bains, and 500 West Peach (the arson site) was her home. However, there is no indication in the game for any family relation between her and the Bains brothers.