By Robert Windrem and Jim Popkin, NBC News

Is this an opportune time for a terrorist attack? Could Al-Qaida use the current financial distress and political uncertainty in the U.S. to magnify its power?

U.S. intelligence officials say no. They suggest that while Al-Qaida may want to be "part of the conversation" in the U.S. presidential election, there is no "specific or extraordinary" threat information, nothing to indicate that terrorists are capable of taking advantage of the current situation.

"They attack when they can, when they have an opportunity," said one intelligence official, adding that terrorists have wanted to attack the U.S. but have tried and failed on several occasions since Sept. 11. "For whatever reason, they have not seen the conditions they need to succeed," said the official.

Indeed, NBC News has obtained a "note" by the FBI and the Department of Homeland Security that debunks recent Internet reports predicting a terror strike inside the United States prior to the elections or the inauguration. The note was distributed yesterday to thousands of U.S. law-enforcement officials, and authored by the Extremism and Radicalization Branch of the Department of Homeland Security and the FBI's Threat Analysis Unit.

By Jim Popkin, NBC News Senior Investigative Producer

The Department of Homeland Security (DHS) today issued an analytical "note" to U.S. law-enforcement officials cautioning that al-Qaida terrorists have in the past expressed interest in attacking public buildings using a dozen suicide bombers each carrying 20 kilograms of explosives.

Authors with the U.S. Office of Intelligence and Analysis added that they have "no credible or specific information that terrorists are planning operations against public buildings in the United States." The DHS analysts--after coordinating with the FBI Threat Analysis Unit--said they were releasing the note because "it is important for local authorities and building owners and operators to be aware of potential attack tactics."

By Jim Popkin, NBC News Senior Investigative Producer

Adam Gadahn, the American-born Al-Qaida member, made a new videotape message that offers proof of life, the FBI and Department of Homeland Security said. In a joint bulletin issued Saturday night to U.S. law-enforcement officials, the FBI and DHS said the videotape was likely made weeks ago, NBC News has learned. "The video probably was created in mid September," the FBI bulletin said.

The videotape is the first concrete evidence that Gadahn, the California-born Al-Qaida spokesman, was not killed in a Predator attack in North Waziristan in February, as some publications had speculated. Prior to the release of the videotape this weekend, Gadahn had not been seen or heard from since January 6. That’s when Gadahn released a videotape that threatened President Bush with “bombs and booby traps” during a visit to the Middle East, and when the Al Qaida propagandist ripped up his U.S. passport on camera and denounced his U.S. citizenship.

The FBI bulletin also predicts more messages from Al Qaida in the coming weeks. "We expect Al Qaida to release additional messages before the election" for U.S. president, the FBI/DHS notice said.

By NBC News

A website run by a freelance journalist in California has posted what it calls "highly detailed U.S. government documents proving the whereabouts of now deceased Army microbiologist Bruce E. Ivins on the days the anthrax letters were mailed."

The two-page document is posted on the website for the Enterprise Report, written by journalist Eric Longabardi. Longabardi reports that the documents detail five "precise windows of opportunity that Ivins had to mail the letters, if he was the person who did so in 2001. These never before seen security records detail Ivin's time at the US Army’s USARMIID laboratory in Fort Detrick, Maryland on the days in question relative to the mailings of the anthrax letters."

The documents do not appear to challenge the FBI's assertion that Ivins had time to leave work, drive to Princeton, N.J., and then mail the deadly anthrax letters in a mailbox there.

The two pages of security-access documents reveal Ivin’s whereabouts at the Fort Detrick Army lab on September 17th and 18th and October 6th, 7th, 8th and 9th, 2001, the website said.

By Pete Williams, NBC News Justice Correspondent

Newly released court documents say that Dr. Bruce Ivins, the Army researcher accused of sending the anthrax letters, wrote an e-mail to himself a year ago claiming he knew who mailed the letters.

"Yes! Yes! Yes!!!!" he wrote, sending the e-mail to himself and using the name KingBadger7 at AOL to send it.  "I've pieced it together.  Now we can finally get all of this over and done with....I should have it TOTALLY nailed down within the month.  I should have been a private eye!!!!"  The message does not say who he concluded was responsible.

By NBC News

The non-profit NEFA Foundation has obtained exclusive footage of what it calls a "would-be terrorist training camp" that operated in a rural section of Canada in 2006. The camp, directed by a confidential informant for Canadaian intelligence officials, included members of the alleged “Toronto 18” terror cell. The "Toronto 18" are accused of conspiring to carry out a large-scale terrorist attack in southern Ontario, including plans for truck bombings and storming local buildings such as the Canadian Parliament and the headquarters of the Canadian Security Intelligence Service, NEFA said.

By Robert Windrem, NBC News Producer

Today's attack on the U.S. embassy in Sana'a, Yemen, is the latest in what U.S. officials call a worrisome uptick in terrorist attacks on diplomatic facilities worldwide. There have been four other attacks on embassies belonging to the U.S. or its allies, this year alone.

Adam Gadahn, the American-born al-Qaida spokesman, warned last August that embassies no longer have immunity from attacks by militants.  In the August 2007 video, "The Will of the Matyr Hafiz Usman," Gadahn warned, "The concept of immunity for embassies and consulates provided for by the international infidel law of the United Nations has no place at all in Islamic law." He goes on, ""Law and logic tells us that these criminals and subversive elements have no place among the Muslims."

By NBC News

In 2004, the U.S. government compiled a 289-page collection of Osama Bin Laden's earliest interviews and public statements. The texts were translated by the CIA's Foreign Broadcast Information Service. The voluminous report has never been approved for public release. But a copy was obtained by Steven Aftergood of the Federation of American Scientists, with a link published in Aftergood's Secrecy News blog.

The government report chronicles Bin Laden's growing radicalization. It opens with a March 1994 newspaper interview, in which the al-Qaeda leader denies being a terrorist. The newspaper benignly describes Bin Laden as a "Saudi businessman."

By Jim Popkin, NBC News Senior Investigative Producer

What if the al-Qaida deputy spoke, and nobody listened? That's essentially what happened today when the propaganda division of the terrorist group released its latest video--complete with a major new speech by the al-Qaida deputy, Dr. Ayman al-Zawahiri--celebrating the anniversary of the 9-11 attacks.

Al-Qaida released the new 90-minute tape to the Al Jazeera television network, played select portions of it throughout the day. But the tape has received scant attention in the United States, especially compared to recent 9-11 anniversaries.

Terrorism analysts say that Americans--and American media outlets--are ignoring al-Qaida messages at their own peril. For many Americans, terrorism concerns are "falling off the radar, as al-Qaida has been silent in the USA (and much of the West) since 9-11," said Michael Sheehan, the former counter-terrorism official for the State Department and the City of New York. "Foreign attacks are mostly background noise. This is troublesome, for if we lose our focus they will attack us again at home," said Sheehan, who is now an NBC News terrorism analyst.

By Jim Popkin, NBC News Senior Investigative Producer

Islamic extremists kidnapped American journalist Daniel Pearl in Pakistan in 2002, and beheaded him several weeks later. Four men were convicted for the gruesome murder, but U.S. investigators believe many more men were responsible.

Now, some Georgetown University journalism students are working to identify all the conspirators and help bring them to justice. In a collaboration with the Center for Public Integrity in Washington, D.C., the students say they already have identified nearly a dozen men who allegedly helped guard Pearl prior to his murder.

The classroom project is led by Asra Nomani, a former Wall Street Journal reporter who was with Pearl in Karachi, Pakistan, just hours before the kidnapping. "Danny always had my back," she said. "And now, with this program, I feel we have his back."