Commentaries On The 9/11 Commission Report

By The Disaster Center
The Disaster Center
August 27, 2004

How Name Matching Works

Recently it was disclosed that Senator Ted Kennedy and Representative John Lewis had some trouble getting through the name-check process prior to boarding commercial aircraft. Ted Kennedy’s name had ended up on the "no fly list." Congressman Lewis figured that he was on a list of people subject to special search because every time this frequent flyer flew he was subject to an extensive search.

The number of people on the lists was supposed to be a secret. Yet, if we divide the total number of the members of congress (525) by the two we know are on a list, multiply that ratio by the population of the United States (294,000,000) we can estimate that 1,120,000 names of citizens of the United States are associated with a name on the list.

Senator Ted Kennedy's name was on the no fly list because someone, who used his name as one of his aliases, disrupted a flight, which was then diverted. TSA reports that the name was mistakenly place on the no fly list. (Apparently if you cause a plane to be diverted it is not significant enough act to be placed on the no fly list.) Representative John Lewis was permitted to fly but subject to the most stringent search, when he attempted to board commercial airlines. Because Congressman Lewis was only searched he was probably on the list because someone with his name is a wanted criminal suspect.

We can estimate the frequency of names used in the United States by using tables developed by the US Census Bureau. Kennedy is the last name of 0.067% of the people in the United States. Ted is the name used by .064% of males. If we use 294,000,000 as the population of the United States and assume that half the population is male, we can calculate that about 32 people in the United States use the name Ted Kennedy. If Senator Kennedy uses his proper name, Theodore Kennedy, which he shares with 0.123% of males, we can estimate that TSA considers that these 62 people are too dangerous to be permitted to fly.

When we look at the name of Congressman John Lewis, we find that John is the second most popular male name, used by 3.271% of males and Lewis is the last name of 0.226% of people. Using these name frequencies we can estimate that 5,544 males share the same name. Unlike Senator Kennedy, TSA permitted Representative Lewis to fly, so we can conclude that TSA allows people who may be wanted criminals to fly. TSA suggested to the Congressman that to get around this problem he should provide the booking agent for his flight with a middle initial and that in this way he might be able to avoid the more comprehensive search boarding a plane. Congressman Lewis has reported that this worked.

If this was the way that TSA’s namebased search is works then it is useless. Ted Kennedy may not be permitted to board a plane because he is a dangerous person, but Theodore would have no problem. John Lewis may be subject to an extensive search but John D. Lewis would not.

There are a large number of indexes used by law enforcement agencies around the United States. These have to some extent been combined at an expense of over 400 million dollars. The most likely indexes to be used for background checks prior to boarding commercial airlines are the NICS: Prohibited Persons Index (PPI) and the National Crime Information Center files.

There are over one million names in the PPI. This index includes individuals who were denied the right to purchase a firearm, illegal and unlawful aliens’ records, controlled substance abuse records, dishonorable discharges, individuals who have renounced their citizenship, and mental defectives.

There are over a million and one half names in the National Crime Information Center files. These include wanted persons, foreign fugitives, deported felons, protective order file, convicted persons on supervised release and the national sex offender registry.

If the souce data only consisted of the names of passengers and were matched against the indexes the results would be useless. If names were matched at the rate of Senator Kennedy's name is matched, these two and half million names would generate around 80 million people being matched with names. At the frequency of Congressman John Lewis’ name is matched, these two and half million names would generate over ten billion matches, four billion more matches than the population of the planet.

What the 911 Commission is proposing to do to mitigate this and other related problems is for the States to issue some form of biometrics identification. To associate the biometrics of each person with a name in the index, every person granted such a biometrics would have to be matched against criminal history indexes. Given the current costs of running an FBI fingerprint check it can be roughly estimated that this process would cost around ten dollars a person, or roughly 3 billion dollars per person to cover every person in the United States. This would not include the capital costs of the verification system.

This assumes that TSA has a record that will enable every terrorist to be identified by the use of a biometrics check. TSA will not and the way for terrorist organizations to work around the problem is to recruit individuals who don’t have records.

If we look at historic acts of terrorism what we see world wide at most 1 out of 33,000,000 people may engage in terrorist acts in a given year. Most of these acts could also be classified as criminal acts in that the terrorists derive a profit from the activity. In the history of the United States terrorist acts, involving citizens, the ratio is considerably higher, closer to 1 out of 100,000,000 every year.

Even if the system is set up it is going to have an error rate. With CAPS I, if preventing acts of terrorism is the measure of the system, the error rate was 100%.

The system will not work for its stated purpose. What the system will do is to create an external and internal network of police background checks for the purpose of monitoring the movement of people through our commercial transportation network.

Commentaries On The 9/11 Commission Report
For Those Who Loved Them
Risk/Threat Management
The Terrorism Center
Deep Institutional Failings
WMD -- Weapons of Mass Destruction
The 911 Commission Report and the Markle Foundation's Recommendations
An Example of Data Matching
The Accuracy of Data Matching
What the United States Stands For
How Aviation Data Matching Actually Works
The 911 ReportThe complete Commision Report in PDF format (7.4 MB)

Christopher Effgen [send him an mail] is the owner of the Disaster Center web site, and has been active in reporting about disasters by digital means since the site was established in 1996. He has authored articles dealing with wide variety of disaster related topics including risk/threat management, neural networks, the science of disaster communication, and compiled numerous disaster related statistics (many of which are hosted on this site). He is active as a participant in national and international forums promoting disaster mitigation towards the goal of sustainable development.

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