I would send his security deposit to last known address via certified mail.

I plan to get an additional checking account for the property, with a sub account for security deposits.

We are doing this to have 3 years to secure financing (long story).

You also are able to secure really advantageous debt on a A class assets which is another angle a lot of investors take when buying in these neighborhoods.

The landlord will say the the rents are current and the tenant will confirm the lease , terms and duration, and security deposit.

For example, you buy the place and the tenant could claim the Seller allowed them to paint the walls black or that their security deposit was twice what the Seller claimed.

Like where I live, it's normal to do one month of rent for first, last, and security deposit. 

A majority don't even make it 18 months from shiny new license to toes-up in the parking lot.Leaving the relative security of a 9-5 W-2 job - especially one with benefits - is a risk that should be undertaken only with a solid plan for surviving startup. 

The latter being the biggest issue, because we're able to fix immediately, and bill immediately thus leaving the security deposit in tact at move out.I just realized I read the second reply as the OP, but I can't edit it out.

Lack of social security in older age.