I've been having a big problem with tenants in Detroit. They move in and 2nd month don't pay. They know the system and stall court hearings and end up staying in the house free for months. By the time I get them.out the house is destroyed and a filthy mess and the yard looks like a jungle.

Then....here's the kicker, on the way out they steal the furnace and hot water tank. 

I just rented a house and it's the 2md month and the tenants.dont pay and already said they're going to court. 

They have only been there 1 month. They obviously moved in with the intention to not pay after getting in. They broke the porch and security door, haven't cut the grass or cleaned drainage area in front of the house, they have not paid for trash pick up.and when I was in the house last there were multiple bags of trash piled up inside.

I just fixed the house from the last tenants paint, floors  etc. Re pipes the entire house with pex because the last tenants purposely broke the plumbing after being evicted,  I put a brand new furnace and hot water tank in because the last tenants stole it after being evicted.

They were supposed to get internet so the security cameras could be installed said it would be this week but lied. They have someone living in the house who is not on the lease and say he's just " visiting."

Im seriously considering just changing the locks and being done with it. 

Whats the worse they can do? Try to sue me for damages? If they can't pay rent and trash pick up how will they pay an attorney? 

Going the legal route with professional tenants cost thousands of dollars. They'll sit for free then steal the furnace and hot water tank on way out. It's happened twice now. 

If I lock them out, will.the police make me let them back in or can they legally break in or is their only recourse civil court?