FBI treating serial bomber as domestic terrorism

The device sent to the Time Warner Center was a "live explosive device," NYPD Commissioner James O'Neill said at an afternoon news conference, adding that police were also investigating an envelope containing white powder that was found as part of the "original packaging" of the device.

Law enforcement officials from New York to Florida are examining clues to find the person or persons who sent 10 packages containing what appear to be explosive materials to prominent Democrats, critics of President Donald Trump, and to CNN’s New York offices as authorities classify the incidents as domestic terrorism.

Three new packages were detected Thursday — two intended for former Vice President Joe Biden and one for actor-director Robert DeNiro — each bearing the same markings as the seven packages detected earlier this week.

The devices mark one of the most serious attempts to stoke fear and terror in the US in a period that has already seen a number of violent political attacks. The apparent bombs, while rudimentary in design, according to law enforcement officials, targeted two former US presidents, a former vice president and potential presidential contender, and numerous outspoken critics of the Trump administration.

Investigators are reviewing security footage from the CNN building and examining the packages themselves for potential clues, according to current and former law enforcement officials.

“Everything is a clue,” a law enforcement official said.

As authorities examine clues, they are also finding more questions to answer.

One key question authorities are puzzling over is why none of the apparent bombs detonated, a second law enforcement source said, raising questions about the skill and motive of the bombmaker.

This person said either the bombmaker was good enough to ensure none would go off and never intended them to explode or it was poorly constructed. Authorities consider the bombs to be potentially destructive because of the presence of what is believed to be pyrotechnic powder. Though it appears they were handled through the postal system — and thus jostled and moved — without triggering any explosion.

The FBI’s counterterrorism team is leading the investigation and has classified it as a domestic terror matter, the law enforcement official said. That classification is based on the absence of other information and could change.

The Secret Service, US Postal Inspectors, and ATF are also working on the investigation with various state and federal offices. The FBI said Wednesday it is possible additional packages could have been mailed to other locations and not yet discovered.

The bombs were packaged in manila envelopes with bubble-wrap lining, according to the FBI. They each bore computer-printed address labels and six American flag stamps. Some went through the US mail service while others appeared to be delivered by individuals.

Investigators will be looking for fingerprints on the package, on the back of any tape that may have been used, and on the stamps and labels. If the seals were licked, investigators may be able to pull DNA from the saliva, officials say. They will also look for any hairs or other materials that could help identify the sender or location.

Other information on the packages will also be rich investigative lines. If the packages were scanned by the US postal system, investigators may be able to determine which machines scanned the documents and when. However, unlike FedEx or other private mail delivery services, the US mail system is not set up to track every single piece of mail.

Investigators who traced a string of package bombs in Texas that killed two people and wounded five in March used those same tools to pull DNA from the packages.

In addition, investigators used signals from cell phone towers to help narrow down the potential suspects in the area at the time the packages were dropped off, according to a law enforcement official. They relied on closed circuit cameras to narrow the field further, the official said. It took investigators 18 days to track down Mark Anthony Conditt, who killed himself with one of his own explosive devices.

Those tactics are likely to be deployed as authorities trace couriers and any individual who may hand delivered the packages. Authorities believe the package sent to George Soros, the billionaire philanthropist who has backed Democrats, was dropped off at his residence in Westchester County.

Investigators believe some of the packages may have originated in Florida, according to one law enforcement official.

The bombs themselves would be dissected. According to a law enforcement official, the bombs so far appear to show the presence of a sulfur substance, which would be the ingredient that was intended to explode. Authorities will examine the components of the bomb and look for clues as to where they may have been purchased and any similarities or differences between the individual packages. Pipe bombs are inherently unstable devices and could be set off simply by handling them.

Outside experts have pointed to the lack of a triggering mechanism, suggesting it was never meant to explode. The device includes very common components, making it more difficult to get clues from the signature of the bomb. But the components could still provide clues — like the clock and the tape used.

New York City Police Commissioner James O’Neill told CNN Wednesday that investigators are reviewing security video to try to identify the courier who delivered the package to CNN’s New York office. O’Neill said he was “pretty sure those images will be caught on video and we’ll be able to find out where that person came from before they entered the building and where they went to after.”

New York City Mayor Bill de Blasio told WABC Thursday the device detected at the offices of De Niro in lower Manhattan is “very similar to the other devices located in the last 48 hours and it all appears to be from the same sender. That investigation is ongoing.” He said the device was taken by the bomb squad to its location in the Bronx for analysis.