When the cops get there, explain to them how she threatened you out of your $20, and that currently no proof to sustain her accusations has presented itself. If you're innocent of her claims, you should have nothing to worry about.

Did she have proof?

should have kept the money.

Sorry OP but you need to learn to stand up for yourself. If you didn't do it then you had no reason to give your boss anything. Losing your job over a theft allegation is far far worst than quitting. Quit if that's what it takes, but never pay back stolen money out of your own pocket. I'm a manager and one of my employees does this kind of thing all the time. If her till is short at the end of the day she'll pay it back from her own money without telling anyone. No matter how many times I tell her to stop she keeps doing it hoping I won't notice. There's a really good chance that she's going to end up losing her job over it because all I can see for sure is that her till never adds up and she's hiding it: to protect someone? because she did take it and lost her nerve?

Whether you did it or not. Handing over the cash is an admission of guilt. Should 've stuck to your guns. So for that YDI

A whole twenty dollars is missing! Better call the police and waste yet more of their time looking for a minute sum of money!

By offering up your own money you basically said I did it I'm sorry here's the money YDI

You should have stood your ground and if there are security cameras which most places have these days then those would prove your innocence anyways good luck

what an ass I've had bosses like that they're bad news and will get worse if they see they can take advantage of you

you should not give her your money