I don't think that detective Jin Is dead as in 11th epiosde of S2 you watch that they don't show the full autopsy of Jin and The call exchange between Kang Doha and son ji yoon at NFS and also the bomb blast that happened on the roof didn't show the full explosion . I think that they try to make a fool out of Dex to catch him . They all know that Professor Han is Dex but pretend to catch him . Bro you should watch this drama . You are going to a absolutely hooked to it . Let's all hope that decective Jin is not dead .