18 Unit Apt Complex in Distress

[Lawrence Barnes]

Hi Bigger Pockets Family!

A investor friend of mine, purchased a 18 unit apt building under lease option with no money down. There are two mortgages that he assumed that total 5500 per month. Each unit is renting for about 600/month and apt is at 90% occupancy.

The property is in good shape structurally but has low-income tenants that are causing problems. 

The goal is for him to slowly replenish the complex with more quality tenants. The taxes are behind 8,000 dollars and there are about 2,000 in repairs that need to be done. 

I can assume 50% ownership for 10k to take care of taxes and repairs. I am wanting to find out if this sounds like a good deal and if so, how do I protect myself on paper and ensure that I am legally entitled to my share of profits?

thank you in advance!