Does my brother have a case to seek damages for pain and suffering and emotional distress against his ex-fiancé after the case was dropped?

My brother was recently deceived by his now ex-fiancé. She lied to her entire family about my brother. This led to my brother having an altercation with her brother. When my brother knocked on the door to speak with his fiancée, her brother pulled a knife and spit on my brother. My brother walked away and called the police. The police arrested my brother for assault, burglary (and something else I cannot remember). My brother lost his job, (he cannot transfer to another site until the charges are dropped). He lost his job (as he transferred to a position in another state so that he could start their life together). This has caused extreme emotional distress to my brother and my family. The family found out that she lied about everything. They have gone to the police stating that their daughter lied and are trying to get the charges dropped.