To access that, click your phone, then the phone-and-stylus icon at the top of the window. Once the clue is on the board, it'll be mirrored to your Sim's phone notebook. Regardless of the tool you use, after the action and animation cycle finishes, you'll get a clue to the perpetrator. Try to follow the objectives list so you can maximize your job performance gain. Or, you might have to analyze a clue with the Spectrum Analyzer object. Then select any clue you have oddly you can select a clue from a previous case. One example is that you may use a computer and use the Crosscheck Police Database interaction. The process is the same either way, but should be dictated by what's on your objectives list. To deduce clues, you'll need to interact with objects based on what exactly you gathered. If you can't solve a case in a single day, focus on other objectives until you are required to head home. If not, don't worry: cases remain outstanding for as many days as you need them to be. Once you're back, you'll need to start working on the case if your objectives want you to. Eventually your only objective will be to return to the police station. When you leave the crime scene, you will not be able to return, so be sure to gather all the clues and witness statements you can. Note that you can take photos and collect samples of the same evidence spot. Keep your eye on the objectives list to see what exactly you need to do in any crime scene. Clues are fairly easy to find: just look for any miscolored area on the ground as if someone sprayed paint on it, or any dislodged and damaged objects. You'll be tasked to interview witnesses or look for clues.
The crime scene is always a random house. You can also use the map to teleport to the crime scene. Once you've got it, you can set up a new case file with the case map. To start out, you'll need to interact with a computer in the station.
Usually you will be given a case to work out. Patrol is an uncommon task in the detective profession. When you're ready to leave, use a self-interaction to return to the police station. To pass this objective, you'll need to either use a Funny- or Mean-type interaction, depending on how you want them to view SimCity's finest.
In this case, the Friendly-type interactions will not help. You may also be tasked with chatting with civilians.