In South Carolina? Seriously?
Reading the story it appears that her sexual orientation had been known for a long time. But she probably didn't flaunt it and just happened to be a good cop who worked her way into the chief's job. As for why she got canned, I can't tell if her bigger crime was being gay or for looking into the mayor's crony and his legal violations.
Let see, a new boss comes in that you worry probably doesn’t like you. You go to war with him. Well if you don’t get him, you get fired.
I have seen it happen more than once. Sexual preference was never an issue in such matters.