if its from down south it could be one of the cooters or even a chicken turtle, There are more than two types of sliders. Yes the more common farm raised ones are red ears and yellow bellies. Pics would help
True any big basking type is a possibility but the green color makes things like cooter, redbelly, chickens, painteds, stuff like that less likely. But you're right, pics would most definitely help
Red-eared Slider, Yellow-bellied Slider, in the end they're still Trachemys scripta. I think the only way we are really going to solve this is if we see a photo of this mystery turtle.