What type of turtle is this?

I just moved into a new apartment. The previous tenant had a turtle that she kept after a breakup, but she neglected it for at least the three weeks that Ive had access to the apartment while moving. So I offered to keep it, because I want it to be happy and cared for. However, she isn't sure what kind of turtle it is and I'd like to know so I can care for it as best I can. She guessed it was a sawback.

[Link to photo](https://imgur.com/a/JEUVaK0)