This is my first post, please be gentle.
A few years ago a friend of mine was assaulted by her boyfriend, he gave her a black eye and broke her ribs, puncturing her lung. The state was going to prosecute but ultimately dropped the case because she had changed her statement and there wasn't enough evidence to dispute his claim that he had just pushed her and she had sustained her injuries by falling onto a cast iron drying rack.
We thought it was a one-off, they had been together 5yrs with no previous violence. It has now come to light that he went on to give his next girlfriend a black eye and the next girlfriend after that. These are the only girls I know about, but there are possibly others. They have photographs of their injuries.
Is it worth going back to the police? Would they do anything? I'm concerned that he will continue to attack his partners in future unless something is done. If they dropped a case for lack of evidence the first time, would they pick it up again if other victims come forward?
I'd appreciate any advice you can give.