Recently my father kind of rescue this turtle from a house he bought, but I'm not sure if it is a RES, because he doesn't have any red mark in his head, also the shell is diferent than the others that we have.
I think it is, you can see the faint light orange stripe running down the side of his face. There's always the chance that he's a hybrid...I'm terrible at recognition so don't take my word for it, more experienced members will respond later.
What does the underside look like? It can be some sort of slider.. or it could be a RES that hasn't been cared for properly or a hybrid as RESowner said.
The turtle seems pretty large, and RES at that size usually don't have that colorful of shells. Facial features (the stripes) lead me to RES ,but the shell like Steve said looks like a painted.