In the page's words:

Follow the murderer's trail right through the city center! In City-Krimi, you set off in small groups on an exciting manhunt and explore the city of your choice in a unique way! Question witnesses, visit crime scenes and guard shady characters. Will your investigations lead to success? Combine the results together with your team of investigators. Now it's up to your logic to make sure the handcuffs click and the culprit is caught.