No lease on commercial property Virginia

[Tracie Van]

Hopefully this is the right place to ask.

Brother in law has been renting a garage for past 8 years with no lease. First mistake. Owner died about 4 months ago. Kids step in and they are not renewing lease. That is fine. They need to be out end of June. BIL paid cash for first month's rent and last month's rent. No receipt given. BIL assumed he did not have to pay for June since he "paid last month's rent" with original owner. Another mistake. Now the kids sent him a notice that he is past due for June. 
I do residential in WI so I have no idea what if any rights they might have.

Thanks on advance for any help or guidance.