Then he tells the police you were aware.

So I was at my unit today and the neighbor told me that the police knocked on her door a few days ago because they had knocked on the door to my building and no one answered.

Contact the local police and see what is required for the children to be arrested for trespass.

@John Collins Here, that usually indicates it’s owned by a police officer, judge, politician, etc. who have the right to not have their address/ownership listed in the public records for personal protection reasons. 

If that doesn't work, you might have to go to the extent of calling the police and having him "trespassed" from the property - meaning that further trespass will subject him to arrest. 

Good idea to check with police too, they do not have restrictions about expressing opinions like a realtor might or at least that has been my experience.

If your house is anywhere east of summit you’ll have the issues but I’d look on Facebook marketplace and definitely file a police report.

Do you realize how many people think they will help their case by talking to attorneys or police and end up screwing themselves?

I called 911 and Police arrived but due to these lax Texas laws towards the tenant, they could not offer any help.

Growing up I watched my parents work their tails off as a police officer and special ed teacher.