Prime suspect with Helen Mirren has subtitles (the region 2 DVDs). Many of the Poirot´s movies, especially the 4st, 5th and 6th have subtitles for the hard of hearing. An old British mystery serie but very, very good and with the additional bonus of subtitles is Cadfael with Sir Derek Jacobi, based on the romances of Ellis Peters (also region 2 DVD). You can also check Miss Marple´s series (the 1st, 2nd and 3rd has closed-captions, but the 4th and 5th have subtitles). Good luck!