Suing for false statements and sharing inaccurate job performance reviews
Here's something you might do. Have a friend call the store's human resources department or personnel office. The friend tells them you have applied for a job with them and he is looking for a recommendation from former employers. If the business is smart the only thing they will tell your friend is that you worked for them from one date to another date - period. If they actually tell your buddy that they fired you for groping a customer, that is actionable - TELL YOUR LAWYER. You also do not have to wait to be terminated. Companies give you a negative job review first because they want to get rid of you and build a false record trail before actually letting you go in attempt to make it more difficult for you to sue. Lawyers are well aware of this common trick so take action against your employer as soon as possible and do not wait to be terminated.
I would also like to add (since I looked into the costs of legal action a while back), that unless you know an attorney who will give you a massively reduced rate, suing the company is a VERY EXPENSIVE proposition. The quotes to me were $10,000 for representation up to and inclucing a settement discussion; $30,000 to take the case to a formal trial.
Also, as was pointed out to me, the courts care about ILLEGAL activities, not unethical activities. So, if your boss makes the mistake of saying nasty things about you, unless you can PROVE what they said was not true (and the burden of proof is on YOU), you will spend tens of thousands of dollars -- for nothing!
Whether anyone likes it or not, the original post had it right. After almost 40 years in business, including 30 yrs running my own company, I learned back when the earth was still cooling from the corporate attorneys that all you ever give as a reference is to confirm the individual was employed and the period of employment. Companies today hire essentially private investigative services as well as have professionally prepared and analyzed profile exams so there isn't much of a way to hide anything. But as for a reference, it is minimal information that any manager will disclose. If you push and he's had it with you he will recomend you either call HR or Legal where they are far more adept at telling you to go away.