With all the “American Idol” and “24” knockoffs littering the TV schedule it’s refreshing when a new show carves out its own original place, and Spike TV’s “Murder” does just that.

It takes this and that from any number of TV series to come up with something truly unexpected: a reality show in which real people solve real crimes.

If only the execution delivered on that promise.

The series, which debuts tonight at 10, is a clever hodgepodge of “Dateline”-style true-crime documentary, “CSI”-style procedurals, and a team-based reality competition. “Murder” aims at appealing to couch detectives who work to uncover the murderer before William Peterson does or before Chris Hansen gives it away.

The setup: Two teams of amateur detectives are set loose to solve a real crime. At their disposal are crime scene re-creations, evidence gathered at the scene and interviews with coroners and the like.

The idea is unquestionably inventive, if a little squirm-inducing, but "Murder" is undermined by sloppy editing and a cumbersome narrative structure.

The narrator, host and judge is Detective Tommy Le Noir, a longtime, no-nonsense veteran of the Arlington, Texas, police department. Most of the contestants have some law enforcement connection. The premiere includes a law professor, a law school student and a fireman.

The two teams of three are given some basic background on the murder: as it turns out, an actual case that's already been solved. They then have 48 hours to solve it and deliver the goods to Le Noir, explaining exactly how, why and by whom the crime was committed.

Things quickly get messy. The teams are given access to a re-creation of the murder scene, complete with dead bodies (mannequins, actually), blood and even bits of brain. The teams must collect evidence and develop theories without contaminating the crime scene. They talk to a real coroner about the cause of death and the murder weapon. They look at interviews with suspects.

The process is often entertaining. As soon as the competitors come up with a theory as to what might have happened, something emerges to prove them wrong. The contestants were obviously picked for their strong-willed personalities, and there are the predictable ego clashes. Le Noir is wonderfully prickly, barely able to hide his impatience with his apprentices’ shoddy work.

But as the episode progresses, the intriguing moments are undercut as the producers snip and cut to fit the series into a preconceived format.

It makes for choppy moments. A fascinating interview with a coroner is cut short. The introduction of possible suspects is clunky. And the re-creations of the suspect interviews are so poorly done that they nearly derail the show all by themselves.

Because of some confused editing, it's unclear at times which team is discovering what piece of evidence or where exactly they are at a given moment. Maybe the producers should have had the groups, named the “Blue” and “Green” teams, wear color-coded uniforms.

In the end, "Murder" is one of those very occasional smart ideas that deserved a bit more time to brew and a lot more planning.