Depends on what their job is, if they are licensed to carry as typical officers of the law and licensed to carry concealed.  This is the website for the Texas Penal Code regarding weapons: http://www.statutes.legis.state.tx.us/SOTWDocs/PE/pdf/PE.46.pdf.  Of particular note are the following (remember to read the statutes in their entirety -- don't simply glance through). Review Sec. 46.03, especially regarding the defenses to prosecution.  You will find your answer.Hope this helps.  If you are being prosecuted and you are the "jailer", then hire a lawyer.  Try www.attorneypages.com or the Texas state bar.