- This article is about the original rendition of the city. For The Conspiracy rendition, see Grimsborough (The Conspiracy).
Founded by William Cooper in 1845, Grimsborough is divided into a total of six districts in its original rendition, with the Grimsborough Police Department (GPD) acting as the law enforcement agency that serves the city.
Grimsborough in the first season features the first fifty-six cases of the game, which are found located across six districts:
Industrial Area is the first district investigated in Grimsborough. It is a worker-oriented district ravaged by organized crime and gang activity, more specifically the gang war between The Vipers and The Skulls, as the rookie player starts to find their footing in the district.
Based on Wall Street and Central Park, Financial Center is the second district of Grimsborough. Roman Harris, known as the architect of the city, is the one who designed and built the Financial Center, a business-oriented district. The district is centered around a powerful and corrupt businessman who is motivated by greed, as the police investigate crimes in the financial district.
Historical Center is the third district of Grimsborough. Founded by Baron Salvadore, it features many historical novelties of Grimsborough as well as being near a forest preserve and a lake. The district mainly deals with various historical crimes and murders that leads up to the imminent Dog Pageant contest in the district.
University is the fourth district of Grimsborough. As an aptly named district, it is a schooling institution with an accredited baccalaureate college, a football field, and several schooling fronts. While the police initially came here to investigate crimes at the schooling institution, the police eventually discover the markings of a serial killer in various murder scenes, leading them to stop the serial killer.
Maple Heights is the fifth district of Grimsborough. Considered to be the most affluent district of the city, it deals with self-centered individuals as well as people who pride themselves of their wealth. The district focuses on the Mayoral Elections as the police investigate crimes among the rich and affluent of the city.
Airport is the sixth and final district of Grimsborough. The district focuses on digging deep into the gloomy mysteries of Grimsborough that need to be unearthed, requiring investigation of a crime scene from the past (with the events dated from 1642–1649) in each case, before a notorious secret society takes over the city.
- In the desktop version of the game, players must complete It All Ends Here in order to make the Airport district appear on the map. In the mobile version, however, Airport is visible on the map from the very start of the game.