does a warrant ever expire?
The only time a felony warrant would expire is if the District Attorney decides to dismiss the case.
Depending on the warrant there may be a due diligence problem in the future...
Criminal Defense Attorney
Mr. Martinez is correct a State of Texas felony warrant never expires. However, once a person is arrested, the arresting agency will confirm whether the Texas district or county attorney that is responsible for prosecuting the case wishes to extradite the arrested or detained person back to Texas. Based upon the severity of the case and the jurisdiction, the prosecutor may or may not want to extradite. Additionally, if the case is one that can be described as a Cold Case, or the defendant is a resident of another case contact a local attorney immediately. If the case involves a citizen outside the State of Texas it may be possible to force the extraditing jurisdiction (E.g. Dallas County District Attorney’s Office) to produce sufficient evidence verify the person in custody is the same person sought for prosecution. If the Texas authorities cannot sufficiently provide the person’s identity, and probable cause then defendant will not be extradited. See Uniform Criminal Extradition Act; Texas Code of Criminal Procedure Article 51.13; http://tlo2.tlc.state.tx.us/statutes/statutes.html
Other issues consider in a possible extradition case, speedy trial violations, wherein the prosecution has not been diligent in its responsibility to locate an individual to bring the person to justice. It may be possible to show that the statute of limitations has expired and the case may not be prosecutable. Finally, your local counsel may need to hire counsel in Texas to work the problem from both sides; I recommend you first find local counsel where you live to address any problems that may be lurking in Texas.