You have provided a lot of information for me to work through. I'm going to start with the issues as I see them, please let me know if I overlook anything.
It seems your son may be in line for a change in attorneys. To begin with, it does not appear that the criminal matter is being properly addressed. Additionally, he may well have a case against the police department for the excessive use of force.
First, you should begin with your state bar association. The Texas State Bar has a website, it is located at http://www.texasbar.com/.
I do not know your county of residence but your county bar association likely has a similar site that will be more specific to your location.
Additionally, Martindale Hubbell is a national organization that rates attorneys across the country. Their website is located at http://www.martindale.com/.
Another nationwide website is located at http://www.avvo.com/. This site lists attorneys by geographic location and area of practice.
Additionally, there is quite likely a legal aid society in your area. A quick internet search and/or phone book search should locate the society closest to you.
Each of these resources will have a wealth of information as to attorneys in your area that handle such cases and that would provide services for free or at a reduced cost. I would suggest you check each site out and you will surely find a great number of attorneys that meet your needs. Pick a few to meet with in person so that you can thoroughly explain your situation and then retain the one that you feel can best represent your interests.
A note as to costs, an attorney taking on the police brutality case may very well take the case on a contingency fee basis, meaning he doesn't get paid unless your son gets paid. As such, you wouldn't need to worry about coming up with any fees to begin representation.
Also, several customers have asked how they may direct a question to me in particular. If you specifically want me to assist you in your legal matter, just put "FOR JOSEPH" in the subject line and I will gladly pick up the question as soon as I am on-line.