Idris Elba has played troubled detective John Luther in three "Luther" miniseries since 2011, but he is now focusing on making movies, such as "Pacific Rim" and "Long Walk to Freedom."
"I've written the script and we hope to get the film made next year," the BBC said Cross told the Edinburgh Television Festival about the "Luther" prequel.
"Idris is a brilliant leading man and we've hoped to turn 'Luther' into a movie for a long time," Cross said. "It will follow his career in the earlier days, when he is still married to Zoe, and the final scene in the film is the first of the initial TV series."
The writer admitted the TV version of "Luther" is "finished" because Elba had "gone on to be a big movie star."
The third "Luther" miniseries is to have its U.S. premiere Tuesday on BBC America.