Dealing with sellers avoiding things

[Rainier NA]

Hello everyone I’m a newer investor in St. Louis and I am actively wholesaling. I have a couple of questions, hopefully someone has also been through this. So I have a seller who is very motivated to sell but seems he is hiding some information from me about the property. We are working on a deal for 2 of his properties but one he couldn’t get inside (idk if he has a key or not) and just recent sent me pictures but only 2 of the living room and nothing else. Also I believe their are squatters. But What are some good ways for me to deal with this before putting it under contract ?

Also I said there where 2 properties. This may be a bit of a silly question but should both properties have their own contract ? He wants to sell both together.