"She is the most significant capture in five years," said former CIA officer John Kiriakou, who said she lives up to her reputation as an alleged terrorist 'Mata Hari.'
And there is an eagerness to see what, if anything, she can add to the thin trickle of fresh information on the activities of terrorists and terrorist supporters in Afghanistan and Pakistan, as well as what if any risk she might pose to national security.
Only a "handful" of captured alleged Al Qaeda associates have had the kind of detailed information on weapons of mass destruction that Siddique, who attended MIT as an undergraduate and earned her PhD in neuroscience at Brandeis, had in her handbag, multiple current and former US intelligence and law enforcement officials told ABC News.
"She is a very dangerous person, no doubt about it," said a senior US counter terrorism official.
"This is a major haul, a major capture for the FBI," said Kiriakou. "To find someone who has such rich information, computer hard drives, e-mails, that is really a major capture."
US authorities are analyzing Siddique's saliva, hair, and fingernail scrapings to determine, if possible, what evidence they can find of any exposure to chemical, biological or radiological materials with potential use in weapons of mass destruction, sources said.
"Her education troubled us. We know that she's extremely bright. She's radicalized. We knew that she had been planning, or at least involved in the planning, of a wide variety of different operations, whether they involved weapons of mass destruction or research into chemical or biological weapons, whether it was a possible attempt on the life of the President," said Kiriakou. "We knew that she was involved with a great deal and we had to bring her into custody."
When nabbed by a team of Afghanistan National Police officers on July 17th, she also had in her possession a one gigabyte digital media storage device - a thumb drive - whose contents included a large trail of emails that authorities are now poring over, sources said. Those e-mails, a source involved in the investigation said, are between "what she described as 'units' and what we would call 'cells'."
In her papers she had maps and information concerning potential targets in New York City that sources say included the subway, Times Square and the Statute of Liberty, ABC News has learned. She also carried excerpts from "The Anarchist's Arsenal" and "documents detailing United States military assets", according to the federal complaint against her filed July 31st in Manhattan.
ABC News sources said that she also had information indicating the possibility of "an attack" on Plum Island Disease Center, a secure US government facility off the tip of Long Island, New York where research into foot and mouth disease, swine fever and other animal pathogens is conducted by the Department of Agriculture and security is provided by the Department of Homeland Security.
"We're proud of our role as America's first line of defense against foreign animal diseases," the facility's website notes. "We're equally proud of our safety record. Not once in our nearly 50 years of operation has an animal pathogen escaped from the island."
The remote possibility of smuggling a pathogen off isolated Plum Island was the subject of the bestseller Plum Island by Nelson DeMille. But a terrorist attack on the isolated island would not spread disease, according to homeland security officials familiar with the research activities there.
Interest in Siddique is in itself not new. On May 26th, 2004 she became the first woman wanted by the federal government in connection with Al Qaeda when then Attorney General John Ashcroft and FBI Director Robert Mueller asked the public's help in finding her and six men suspected of links to Al Qaeda.
At that same time they warned, in advance of the Democratic and Republican National Conventions, that Al Qaeda was preparing to "hit the United States hard" that summer.
By then Siddique had been linked to an "ill conceived" and perhaps amateurish plot to "kill all living US presidents", according to sources from three federal agencies. And she had already vanished from public view for about 16 months.
She has also been twice married; once to a nephew of 9-11 mastermind Khalid Sheik Mohammed.
Her name reportedly rolled from KSM's lips when he was captured and interrogated by US intelligence officers. She has also been linked to Adnan El Shukrijumah, a pilot and suspected al Qaeda member also on the Ashcroft-Mueller list.
Shukrijumah, Ashcroft noted, had once lived in Florida, had left the United States and had later attempted to re-enter the country using a variety of passports.
"We know that he has been involved in terrorist planning with senior al Qaeda leaders overseas and has scouted sites across America that might be vulnerable to terrorist attack," Ashcroft added.
By the time of Siddique's capture last month, she had become something of a cause celebre among some human rights activists who believe she was "disappeared" five years ago by the Pakistani government, perhaps at the request of the United States.
At a federal court hearing in Manhattan on Monday, the number of supporters who showed up required the US Marshals to move the Magistrate's Court proceeding to a larger courtroom and also open an overflow courtroom where spectators could listen to and watch the proceedings on closed circuit TV.
They saw Siddique slumped over in a wheelchair, the result of having been shot twice with a nine millimeter side arm after she allegedly grabbed a US Army Warrant Officer's M-4 Carbine and opened fire as a team of FBI agents, US Army officers including the Warrant Officer and a Captain, and interpreters prepared to interrogate her on July 18th, the day following her arrest, according the federal complaint.
"The Warrant Officer saw and heard Siddique fire at least two shots as Interpreter 1 tried to wrestle the gun from her. No one was hit. The Warrant Officer heard Siddique exclaim 'Allah Akbar!' Another interpreter (Interpreter 2) heard Siddique yell in English 'Get the f--- out of here,' as she fired the rifle," the complaint stated.
"Her medical condition is that, she was shot in the abdomen. There are stitches that run from the breast plate area down to the belly button area...layers and layers of tissue have been sewn, sutured. We have heard reports that she has lost a kidney; we don't know if those are accurate but we are concerned about that. There has been intestinal damage, part of the intestines, we understand, have been removed," according to Elaine Whitman Sharpe, one of a team of three attorneys present for Siddique.
Pakistani officials present at the hearing said they had "no information" on the allegations that Siddique had been secretly held prisoner and "no information" to offer on the allegations that their government may have assisted in that capture.
Her friends and family say the young woman, a mother of three, is innocent and being persecuted by the US.
There is some dissent in the intelligence community on Siddique's potential value and some have characterized her as mentally unbalanced and operationally insignificant.
But in an intelligence and law enforcement community that has exhausted the useful information from high value prisoners it has had in custody for as long as six years and has watched the stream of new intelligence go from a torrent to a trickle, she is seen by many as having at least the potential of holding valuable current intelligence about members and associates of Al Qaeda both overseas and in the United States.
