Updated

A third person has now come forward to verify claims made by a military intelligence unit that a year before the Sept. 11, 2001, attacks, it had information showing that lead hijacker Mohamed Atta (search) and other terrorists were identified as being in the United States.

J.D. Smith, a defense contractor who claims he worked on the technical side of the unit, code-named "Able Danger" (search), told reporters Friday that he helped gather open-source information (search), reported on government spending and helped generate charts associated with the unit's work. Able Danger was set up in the 1990s to track Al Qaeda activity worldwide.

"I am absolutely positive that he [Atta] was on our chart among other pictures and ties that we were doing mainly based upon [terror] cells in New York City," Smith said.

Smith said data was gathered from a variety of sources, including about 30 or 40 individuals. He said they all had strong Middle Eastern connections and were paid for their information. Smith said Able Danger's photo of Atta was obtained from overseas.

Rep. Curt Weldon (search), R-Pa., arranged the media roundtable with Smith. Weldon drew attention to Able Danger by speaking about it on the House floor months ago and has publicly called for the Sept. 11 commission to explain why the intelligence information wasn't detailed in its final report.

Besides Smith, Lt. Colonel Anthony Shaffer (search) and Navy Captain Scott Philpott (search) have also gone on the record, saying they were discouraged from looking further into Atta, and their attempts to share their information with the FBI were thwarted because Atta was a legal foreign visitor at the time.

"This story needs to be told. The American people need to be told what could have been done to prevent 3,000 people from losing their lives," Weldon told FOX News this week.

Shaffer and Philpott claim that in October 2003, they told Sept. 11 commission staffers of the presence of Al Qaeda operatives in the United States in 2000 yet little was included in the panel's final report about those conversations.

During Friday's roundtable with Smith, he was asked by reporters about Atta, who was using another name during 1999-2000. Smith said the charts Able Danger was using had identified him through a number of name variations, one being "Atta."

Two sources familiar with Able Danger told FOX News that part of its investigative work focused on mosques and the religious ties between known terrorist operatives such as Omar Abdul Rahman (search), who was part of the first World Trade Center bombing plot in 1993.

An independent terrorism analyst pointed out to FOX News that German intelligence had no record of Atta before the Sept. 11 attack; that's significant because Atta headed up the Sept. 11 Al Qaeda cell in Hamburg. The analyst also questioned how Atta could be connected to Rahman, who was in prison by the mid-1990s.

Smith claims that one way the unit came to know Atta was through Rahman. Smith said Able Danger used data mining techniques — publicly available information — to look at mosques and religious ties and it was, in part, through the investigation of Rahman that Atta's name surfaced.

Aides to Senate Judiciary Committee Chairman Arlen Specter (search), R-Pa., are actively discussing scheduling a hearing on Able Danger and the larger issue of information-sharing between the Pentagon and the FBI.

One of the central Able Danger claims — that military lawyers blocked the sharing of the Atta information from the FBI in the late summer and early fall of 2000 — will be a focus of the committee if a hearing takes place, FOX News has confirmed.

Specter sent a letter to FBI Director Robert Mueller on Wednesday asking the agency to provide to the committee "all information and documents it has in connection with Able Danger, , Lt. Colonel Anthony Shaffer, Captain Scott Philpott or any other persons having any connections with Project Able Danger, including, but not limited to, e-mail communication, notes, phone message slips, memos or any other supporting documentation."

Specter also asked Mueller to make available FBI agent Xanthig Mangum to meet with his staff. Mangum is reported to have corresponded in 2000 with Shaffer, who helped run Able Danger's mission and has offered to testify on its findings, about scheduling a meeting between Able Danger and FBI staffs. No meeting ever took place.

The Pentagon has been looking into what it knew and when it knew it, but defense officials have not been able to verify the Able Danger claims so far. A Pentagon spokesman confirmed Thursday that the department has interviewed both Shaffer and Philpott.

"There's something very sinister going on here that really troubles me," Weldon told FOX News on Thursday, blasting the Sept. 11 commission (search) for not taking the claims more seriously. He said some panel members were trying to smear Shaffer and Able Danger.

"What's the Sept. 11 commission got to hide?" Weldon asked. "The commission is trying to spin this because they're embarrassed about what's coming out. In two weeks with two staffers, I've uncovered more in this regard than they did with 80 staffers and $15 million of taxpayer money."

Sept. 11 commission Chairman Thomas Kean recently told FOX News that the panel is waiting for a response from the Pentagon. Until then, the commission has stood by its work, maintaining that no documents they received from the military backed up the Atta claims.

Weldon added that at least five people on the federal payroll will testify under oath about the validity of the Able Danger intelligence.

"When this is over, the Sept. 11 commission is going to have egg all over their face," he said.

FOX News' Catherine Herridge, Molly Hooper and Liza Porteus contributed to this report.