For example, a prior owner might have an IRS lien that has attached to the property or there may be unpaid estate taxes owed from a deceased prior owner.

Your friend should also check with an accountant or a cross border specialist on the best way to approach this, if they are not already set up to do business in the US.  

If you want more control of your rentals, why don't you look just over the border in NW Indiana.

That is likely asking a lot of an Excel model and is bordering on something that a COTS software model (like Argus) would do.

But when it comes to property within the restricted zone (31 miles from the beach or 61 miles from the border) it must be purchased by using a bank trust or “fideicomiso”.

However, what has intrigued me as of late are the transitioning C neighborhoods that border the B areas that have a potential for appreciation which I'm also looking into.Ultimately, it boils down to tenant selection and the company that manages the property.  

Sierra Crest is actually facing a unmanned cemetery of 2K deceased patients(now a parking lot) who had no relatives.

We work with a couple of cross border tax specialists that help our Canadian clients when investing in the United States.

South of the border you have literally hundreds of lenders.

The owner is deceased, therefore the mortgage hasn’t been paid and is now foreclosing.