A brutal ex-sheriff returns to the small town where she bullied others as a child to investigate a string of seemingly random suicides.

Never start a logline with "When" - I don't know why so many people try this; it isn't compelling and slows everything down, as do all the commas. Try phrasing it as a single straightforward un-paused sentence providing the protagonist, antagonist, conflict, & stakes. And if specifying all four of those things interrupts the flow, find a way to at least imply them.

Going by the other comments here it seems as though you've edited the logline since first posting, as there's nothing in it now to identify the main character's gender, which is often useful to do (though not strictly necessary) as it helps define the character in a very general way. Plus there are other quoted phrases not present. Also I'd be careful taking advice or feedback from anyone using superfluous apostrophes. Anyway here's one possible example:

A retired sheriff returns to the small town where she bullied others as a child to investigate a string of seemingly random suicides.

The point is, it should flow, it should sum up the basic story elements in a quick burst of information...not be a drawn-out, casual stippling of dropped details for a reader to pick up.

A female bully -- well, that's different.

However, as giannisggeorgiou asked, what's the visual for "face her past sins"?? Other than stare at them, what must she do about what she sees?? What action must she take?

A female bully -- well, that's different.

However, as giannisggeorgiou asked, what's the visual for "face her past sins"?? Other than stare at them, what must she do about what she sees?? What action must she take?