A brutal murder has happened and will the detective will be able to solve it? This concept has definitely potential. From my feeling, the setting should a bit different. I would try to take a more real-life scenario where it would be hard to detect the perpetrator like in a house, park, restaurant, hotel. You could also start the scene with the crime scene already happened. In this case, you would really need to rewind everything to find out the criminal. This would also be a portal for multiplayer, where the player has to compete against each other to find the suspect as fast a possible. Do it really have to be a murder, maybe you have to find a pickpocket and that would be maybe much harder. Great job with your work and creativity.