Tenants not getting along

[Naeem Barbour]

Hello BiggerPockets Community,

I currenty have a 2 flat which I have a long term tenant who is paying cash living on the first floor & another CHA tenant who lives on the second unit above her.I wanted to go CHA because of the for sure money that will be coming in every month. Everything in the screening seemed to be cool until they moved in. Since he moved in, it has been altercations on a number of accounts. The first one was him getting into it with my long term tenant's son over a garage parking spot. There were death threats made to the her son made by the new tenant and the police were called. Second incident was his guest getting into it over the washer and dry which is free to wash. They have been inviting family members over to wash loads of laundry. Third incident was the tenant having a domestic disturbance to my neighbor on the first unit saying that a couple was fighting upstairs. I've been feeling like I'm mediating grown ups and adults. Looking for advice on how other experienced investors would handle these situations. If I hire a property management company they will eat up my cash flow. Also they haven't been paying water because its not in the lease and my water bill is above $1k. Just need some insight.