WHEN former Spotsyl- vania County resi- dent Jim Klock set out to write and direct his latest film, "Murder Eleven," he had several extras going for him.

First, as a former detective and police officer who once worked in Alexandria and the counties of Stafford and Prince William, Klock knows the criminal mind and how police think and talk.

Second, Klock--a Los Angeles resident who is a film company exec by day and a writer, actor and filmmaker the rest of the time--works harder than most others. He eschews such things as sleep or vacations to get the next project made.

And finally, he's found an unusual way to motivate himself on a slate of films, from a short feature to start his career to the "Murder Eleven" full-length film that is shot and now in post-production.

"Most of them I did on my own money," said the 36-year-old former policeman, a graduate of Chancellor High School.

Klock held a premiere of his new criminal thriller recently at the Paragon Village 12 theaters in Spotsylvania. In attendance: Fredericksburg Police Chief David Nye, who was Klock's boss not so many years ago when both worked for the Alexandria police force.

A neat wrinkle there: Nye's daughter, Emily, who's now a writer out in California, helped as a story consultant on "Murder Eleven." As he has in most of his other early films, Klock writes, directs and stars in this one.

The film focuses on both the police investigation of a string of murders in Atlantic City and an increasingly unstable man (Klock's character) whose wife comes home early to discover he's holding perhaps the 11th victim captive in their garage.

It's an edgy, intense performance from Klock. But perhaps the smoothest and most professional part of the production is the way he captures how police partners interact as they try to track down leads in the latest killing.

"I try to write what I know," Klock said in an interview during a recent visit to see relatives who still live in the area. "Working in everything from narcotics to a unit of detectives, I got a chance to see various aspects of police work."