For decades, no city has attracted more dubious characters into its buildings than Las Vegas. The lure of quick scores has made Sin City the most vigilant and diligent user of advanced surveillance, identification, background-checking and security technologies. If domestic security were prosecuted as aggressively as casino security, the terrorists that took down the World Trade Center towers might well have been caught. After all, several of them were in Las Vegas as late as August 2001. Here's what Tom Ridge and counterparts still could learn.

It's Aug. 13, 2001. A man of apparent Egyptian descent calling himself Mohamed Atta checks into an Econo Lodge Motel on Las Vegas Boulevard South. That night, as the temperature cools from 105 degrees, Atta falls asleep in the U.S. city that personifies gambling, drinking, prostitution and even culinary decadence. Could any locale other than Sin City be a greater affront to a Muslim fundamentalist?

This was Atta's second documented visit to Las Vegas, Nev., in three weeks. In fact, between May and August 2001, Atta and four other terrorists that the world would later come to know as attackers of the World Trade Center towers and the Pentagon spent time in Las Vegas.

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To this day, whether Atta and his associates were at the time crafting their plan to use airplanes as gasoline-laden bombs is anyone's guess. Yet there is a tragic overhang of investigative irony. Atta, Marwan al-Shahhi, Nawaf Alhazmi, Ziad Jarrah and Hani Hanjour placed themselves in the middle of a city that already had become the perfect laboratory for developing and testing the technologies and strategies that may ultimately determine the outcome of what has come to be called the War on Terrorism.

In the effort to prevent future attacks, the U.S. Department of Homeland Security (DHS) and other federal and local law enforcement agencies are now beginning to deploy the kinds of transactional, facial and other tracking technologies that casinos such as the MGM Grand, the Venetian, the Bellagio and the Stratosphere long have used.

By combining basic information on employees and guests, such as their stated home addresses, the purchases they make, the times they visit town and the movements they make, these casinos have created enormous databases that show not only visitors' playing habits, but their criminal pasts and their connections to other visitors. All to safeguard a $70-billion-a-year gaming and resort industry.

Sure, these casinos use state-of-the-art digital and analog surveillance cameras and equipment to watch the activities of patrons and employees as they move or stop in any given square foot of their property. But they also make use of seemingly innocuous sources of data, such as the card keys guests use to open their rooms or the charges they make at gift shops, to paint a picture of "non-obvious" clues that might reveal unexpected threats to their tills—and their facilities.

By combining decades-old security procedures with these new tools, Las Vegas, despite being the fastest growing metropolitan area in the United States in the past dozen years, recorded in 2001 the fewest crimes per thousand residents (40.5) of any U.S. city with a population of more than 1 million residents, according to the Federal Bureau of Investigation. By comparison, on average, a city of that size reported 77 crimes per 1,000 residents.

More than 38 million people made their trek to Vegas last year for business or pleasure, each "contributing" an average of $300 in gambling losses. But the seemingly strange confluence of entertainment and excess also makes the city a glaring neon target for terrorists, according to officials from the Nevada Commission on Homeland Security (NCHS).

"This is where the bad guys come to play," says Ret. Army Colonel Jerry Bussell, chairman of the NCHS, the state agency charged with finding and implementing the latest technology and procedures needed to fight terrorism. "These [casinos] have been here for years, almost daring anyone to come and take their best shot. It makes complete sense to me and everyone else that this is the perfect place to test and develop the technology we need to fight terrorism."

Indeed, those charged with increasing domestic security, whether in the United States, Spain, Indonesia or other parts of the world, would do well to study how Las Vegas has mastered the art of identifying and detaining garden-variety cheats and thugs and apply them to preventing another organized terrorist plot, according to Alan Zajic, a casino-security consultant with more than 25 years of experience.

With the benefit of hindsight and three months of research, Baseline has examined how the practices that Las Vegas uses to identify cheaters could have been used by the FBI, Central Intelligence Agency and State Department to prevent most, if not all, of the 19 terrorists who took control of airplanes on 9/11 from receiving a boarding pass in the first place. Following more than 20 interviews with casino security chiefs, surveillance directors, security consultants, former FBI agents and members of the NCHS, this review will also show how technologies ranging from "non-obvious pattern recognition" to "name one other" can even today be used by DHS Secretary Tom Ridge and other federal, state and local officials to thwart future attacks.