There is no longer a "look-back" period in Texas. Any previous DWI a person has ever been convicted of may be used to enhance a current DWI charge, with some limitations. Your friend should hire the best DWI lawyer available and immediately. Waiting to hire an attorney is almost as bad as not hiring an attorney at all since valuable evidence may about to be destroyed. The police will not keep evidence of a person's innocence since they are only concerned with proving guilt. It is the job of the defense attorney to make sure ALL evidence is preserved.
Kelly W. Case
Your friend needs a good lawyer because he is going to be prosecuted with a felony DWI. There is no limitation on the use of priors any longer - can be 25 years old and the conviction can be used.
The answer is no the gap in time doesn't matter, however, when the others occurred does. In order to be able to use them for enhancement purposes (making the DWI a felony) the State must prove certain criteria. We need to research to find if they are able to do so. Please contact a DWI attorney to assist you in this matter.