With shows set in Las Vegas, Miami and New York, how long can it be before there's a "CSI: Phoenix" and a "CSI: Indianapolis"? "NCIS" has shows based in Washington, D.C., Los Angeles and New Orleans. After they run through Chicago, Philadelphia and Houston, they're going to have to start turning to smaller cities. Maybe "NCIS: Oxnard" and "CSI: Branson." After that, they'll have go to suburbs and hamlets. "CSI: Apple Valley." "NCIS: Senior Living Community Center, Boca Raton."

At some point, "CSI" will even run out of The Who songs to play over the opening credits.

Since the "CSI" shows are based on real crimes ripped right from the headlines, it makes sense to set them in big cities: There, it's easy to find cunning, evil murderers. There are millions of them. Well, not really, but TV makes it seem that way. Remember "Murder, She Wrote"? Jessica Fletcher lived in Cabot Cove, a little town of 600 people. Someone got killed there every week. That's 52 murders a year, and the show ran for 12 years. I guess it ended because there was no one left in town to kill.

As they add more and more "CSIs," they'll have to start ripping the headlines from smaller and smaller newspapers.

"How do you know this is the suspect who stole the chainsaw-carved wooden bear off your front lawn?"

"Because I was his math teacher all six years he was in high school. And I saw the bear in the back of his pick-up truck yesterday. If he doesn't put it back by this weekend, I'll tell the road crew to stop plowing snow from in front of his house."

And the crime labs in those towns won't have such fancy, expensive equipment to identify suspects. They wouldn't be able to afford it. You won't hear lines like, "We analyzed the air in the room and found a puff of your own breath that you left at the crime scene 18 months ago."

Or, "The handle temperature of these pinking shears puts you in your penthouse at 3:14 a.m. Thursday, when you were supposedly out stealing fashion ideas from transvestite street walkers. Care to change your story?"

Or, "We were able to get DNA results from the sashimi the victim had for dinner, which proves the smoked eel was from southern Maryland, not northern Virginia. Which means the sushi chef is lying."

But without hair samples, DNA swabs, fingernail scrapings, bullet fragments and blood-stained clothing, how will we ever find out who's been TP-ing the trees at the old Westcott place every week? Without lifting prints from the letter, how will we ever know who sent the notice to the local radio station that the Pancake Breakfast at the Presbyterian Church had been canceled -- when it really hadn't? We may never get to the bottom of that one. Some suspect the owner of a local restaurant who's been complaining that all these fundraising church breakfasts kill her weekend breakfast business. But that doesn't make her a criminal. Besides, she is a Presbyterian, so it seems unlikely.

After watching all three "CSIs," I do have one question. And it's not about DNA or blood-splatter patterns or the proper way to weigh someone's brain in the autopsy room. It is this: Are any average-looking people hired by forensic labs, or do you have to look like a movie star to get a job? If you just go by what you see on "CSI" and "NCIS," it seems as if every law enforcement officer had to make an important decision early on in their career: whether to stay in law enforcement or take up high-fashion modeling.

What worries me is that, at some point, as these franchises keep expanding, they will start running out of good-looking actors to play crime scene investigators. By the time they get to "CSI: Nantucket" and "NCIS: Chillicothe," they're going to be down to "facially challenged" actors.

But that's OK: In that case, I might finally get a chance to act. I've been told I'd make a good dead body.

And more than once.