<p>The deaf-mute man charged last year with killing and raping a 16-year-old James City girl may never gain the needed language skills to face trial.</p>
<p>Authorities say Martinez, an illegal immigrant from El Salvador, sexually assaulted Brittany Binger in January 2005 after grabbing her from behind and cutting off her air supply. Police found the girl's body under a tree near Whispering Pines Mobile Home Court, not far from the tool shed where Martinez lived.</p>