can a former employer call your new employer and tell them something about you that would get you fired??

if your former employer fires you and then finds out where your working and tells them that they have crimanal charges against you and tells them what you have done. is that legal?

Generally speaking, that is not illegal. However, your question is too vague to say with a certainty. Do you want to share any details?

In some cases they may very well have a legal obligation to let your new employer know, particularly if they were called as a reference.