The database used to produce the government's terror watch lists is "crippled by technical flaws," according to the chairman of a House technology oversight subcommittee—and the system designed to replace it may be even worse.

In a letter to the inspector general at the Office of the Director of National Intelligence last week, Rep. Brad Miller (D-NC) complained that the National Counterterrorism Center's "Railhead" initiative, designed to upgrade the government's master database of suspected terrorists, "if actually deployed will leave our country more vulnerable than the existing yet flawed system in operation today."

Miller, who chairs the Investigations and Oversight Subcommittee of the House Science and Technology Committee, cited "severe technical troubles, poor contractor management, and weak government oversight," which he said had brought the Railhead program to the "verge of collapse."

The NCTC's Terrorist Identities Datamart Environment, established pursuant to the recommendations of the 9/11 Commission, is the government's centralized master database of people with suspected terror links. Containing some half a million names, it is used to create more specific watchlists used by other government agencies, such as the Transportation Security Administration's much-derided "no-fly" list.

The current TIDE system has its own set of "serious, long-standing technical problems." It requires users to perform "cumbersome and complex" SQL searches rather than delivering straightforward text matches. And its data is scattered across 463 different, poorly-indexed tables.

But the Railhead "upgrade," Miller's letter charges, only compounds the problems. According to his subcommittee's analysis, the new-and-improved system boasts fewer features, hobbles information sharing between agencies, fails to match slight variations in aliases contained on the watchlist, and is stymied by basic Boolean search operators. Miller also alleged that some of the $500 million spent on Railhead already had been improperly used to renovate a facility owned by contractor Boeing.

The NCTC fired back Friday in a statement, calling Miller's description "inconsistent with the facts" and complaining that his subcommittee "has had no interaction with the NCTC or the Intelligence Community on the Railhead Program."