So do a background/credit check, get a full application, paystubs (Call to verify), former landlords phone #s (Call to verify), and other information.

he could have or should have made one call to the building department to verify.. 

Is there some other way to verify his involvement? 

Keep in mind this is sponsor-provided material, not something that the site discovered through research, nor verified. 

Quote from @Timothy Franklin: Hey all,I would like someone who is experienced in wholesaling to verify the accuracy of my understanding of the wholesale transaction.

You want to put everything in writing and be very clear about expectations and responsibilities.You also need to verify the remaining tenant can afford the rent.

I want to enter and secure property now  since she verified vacating apartment, but want to hold her liable for this month's rent. 

Quote from @Lolo Druff: Just like turn signals, you should always trust, but verify that the seller is telling the truth.Your offer to purchase should include a requirement that the Seller provide all documentation and agree to sign an estoppel certificate (also called an estoppel form or agreement).

Like others have said, Id do WHATEVER you need to to get a COMPLIANT sprinkling system up ASAP.

I would like to hear your thoughts and what I need to verify before making an official offer.