What is my responsibility if my tenants physically fight?

[Alyssa Lebetsamer]

Two of my tenants got into a bit of a brawl. It is hard to piece together what happened exactly because the stories don't match up, but it appears that Tenant A threatened/chased Tenant B's guests with a baseball bat after they rang her doorbell repeatedly at 2 AM (they had the wrong apartment), and then when an angry Tenant B confronted her, she yelled and screamed and hit him multiple times with her screen door. So Tenant B (who is male) pushed her and broke her security camera. Tenant A says Tenant B choked her and entered her apartment by force - Tenant B denies this. Police were called and a report filed, but no arrests were made. What is my role in all of this? I know the tenants both have a right the peace and quiet, and to feel safe in their homes. They sort of both crosses the line here. Both are presenting it to me like they are the victims. Any advice???