The Tx Atty Gen has limited roles in criminal cases, and is overwhelmingly used for civil cases. The attorney general can help a local law enforcement agency if that agency asks for it.
According to Chpt 1, Sec 1.09 of the Tx Penal Code, the Attorney General has concurrent jurisdiction to prosecute criminal cases if the local or county DA request their help. Otherwise, they stay out. The Texas Government is set up to remove as much power from central agencies as possible, including the Justice Department. So, unless Harris County asks for their help, their is not much the AG can do.
Then I guess since there is No Controlling Legal Authority, we just roll over. Looks like we sold our soul cheap.