Danger on the Tracks

Detective Susan, together with the police officers Donald and Emily, come to the central metro station. It is a place that, besides the regular passengers, gathers pocket thieves and thieves of expensive phones. Susan and the police officers know about that, but they still need to collect some more pieces of evidence. They are here to find traces that will reveal the identity of the thieves, so they can continue their investigation. Without knowing the identity of the thieves, they won't be able to take charge of anyone, so they have to act very carefully, to take care of every possible detail, so they can finish the investigation objectively. Detective Susan, Donald, and Emily know their job really well but they can also use some help from you. Let's visit the metro station, together with them, and see if you can find what you are looking for. Also, there is a chance that you will find the thieves in their favorite spot, so be focused and do whatever it takes.