Nonpaying Tenant Without A Lease in Texas

[Michelle Hart]

My 86-year old grandmother owns a home in which my uncle (her son) has been living for the past several years. Up until June of this year, she was living in the home, and paid the mortgage. 

In June, we realized she was not being properly cared for, and she moved to Austin to live with me. Uncle has remained in the home. Since she left, my grandmother has been contacted by the City about him illegally storing approx. 20 "junk cars" on the property, and we know he's running illegal poker games out of the back of her house. We suspect (but don't know for sure) that he also has a woman living there with him that my grandmother expressly told him was not welcome in her home.

Every month, he has an excuse as to why he can't/won't cover the $650 mortgage. To date, he hasn't paid a dime to live there, and the mortgage money has come out of my grandmother's very limited SSI check. As of this month, I'm covering the mortgage on her behalf. He refuses to move out of his own accord, and I have quite a bit of his detailed excuses for nonpayment in writing.

My grandmother is adamant that he needs to move out if he's not going to pay rent. We need the equity out of her home so she can afford assisted living. He's been a huge thorn in our side, threatening to file for guardianship over her and/or try to have her declared incapacitated if we don't let him stay in the house. 

I intend to use my POA to move forward with my grandmother's wishes to sell the house as soon as possible, whether to an investor who wants to flip it or someone else via MLS.

My understanding is that even though he doesn't have a lease and is refusing to pay rent, he has to be treated like an ordinary tenant when it comes to the eviction process.

My plan is to drive up there and tack a 3-Day Notice on the door listing the total amount of back rent owed. If he doesn't pay within 3 days, I'll file an eviction proceeding with the local court and follow the usual process.

Should that be enough to get him out?

Given the absence of a lease, should we also list the myriad legal violations and suspicion of an unauthorized tenant on the eviction petition?

Is there any leverage, law or guideline I'm missing that could help me remedy this situation and give my grandmother some peace of mind?