i been working at this establishment for 6 years. I broke up a fight/scuffle with two girls at my job when I was off the clock, security was inadequate. no witnesses & non-conclusive video footage. one of the girls claims I "assaulted" her. no pictures, just hearsay. my employer suspended me until further investigation. I haven't filled out a statement yet.
Chapter 13 Bankruptcy Attorney
Politely talk to your employer or if they have HR and explain your position. However, you have no legal right to intervene or otherwise legal rights under any existing laws because most of such employment is at will. In such cases, you should have called the police and inform your employer immediately.
Only see a licensed attorney before you make any decision. This answer may not be perfect in any given situation. However, more fact may be required by your local attorney.