First off, you really don't have a case against Texas at this point based on a "failure to compare fingerprints". This is for several reason, one of which is the state is immune from a suit for things like this, another is that fingerprint identification can result in different opinions from different experts, etc.
I want to discuss the first one because that is the really big issue. States have what is known as "sovereign immunity" which is based on the old theory that you couldn't "sue the king". In Texas, the state has waived a certain amount of immunity under the Texas Tort Claims Act but it is for very limited purposes. Basically, you can only sue the state for two reasons, damages arising from car accidents or “motor-driven equipment” accidents, and personal injury or death “so caused by a condition or use of tangible personal or real property.”
Neither of these really apply in your case. The federal government will also let you sue a state for violations of your civil rights but that really doesn't apply in your case.
In addition, Texas allows a defendant to "pass the blame" to someone else. In this case, what would happen even if the tort claims act didn't exist is that the state would blame your brother and likely escape liability that way.
This is a very strange area of law and if you have any questions that you ned me to clear up please feel free to ask them in this thread. In addition, if you need additional information on the Texas Tort Claims Act you can see it at the statute itself:
or at this publication:
If your question has been answered then I'd offer my best wishes to you and ask that you please not forget to leave a Positive Rating so I receive credit for my work. Of course, please feel free to ask any follow up questions in this thread. I want to be sure that all of your questions are answered.