NEW YORK, N.Y. (WIVB)- State and federal investigators are working to determine what occurred during the hours, minutes, and seconds before an explosion in the Chelsea district of Manhattan injured 29 people.
“So many years of forensics with bombings have improved the sophistication of investigators to be able to come up with that information not just from a bomb that doesn’t go off, but one that does go off,” said Peter Ahearn, former Agent in Charge with the FBI.
Ahearn also told News 4 the fact that several of the improvised explosive devices officials believe placed by 28-year-old Ahmad Kahn Rahami did not go off, helped investigators to locate him and connect him to the explosions sooner.
“I’m thinking very strongly that it was a fingerprint because DNA would take some time to develop,” Ahearn told News 4.
The explosive found by investigators that exploded in Chelsea was a pressure cooker bomb, likely set off by a cell phone. Federal investigators found residue from an explosive called Tannerite on the device.
The style of IED is also a factor. Authorities found a similar IED blocks away from the explosion in Chelsea; it never wen’t off, and is being examined by investigators.
Ahearn said Rahami’s decision to place the devices where he did is something investigators will no doubt work to understand.
The device in Chelsea went off in an area not widely populated to known to have a large crowd.
Rahami is also under investigation for his involvement in a pipe bomb explosion earlier Saturday in Seaside Park, New Jersey, before the start of a charity 5K race to benefit Marines. That device contained different materials than the two devices in Manhattan, but was also likely set off by a cell phone.
“And then six blocks away at another location in the area, why he picked that area as opposed to why he picked the area down in Seaside which was a military, a Marine Corps fundraising activity for a race. Why he picked that or did he just take a target of opportunity, get in quick, plant it somewhere and get out,” Ahearn said.
“The wiring, the detonator. All of these things leave a trace, or possibly leave a trace that investigators can use,” said Homeland Security expert and professor at Medaille College, Steve MacMartin.
MacMartin told News 4 surveillance also played a big role in placing 28-year-old Ahmad Kahn Rahami near the scene of the blast.
Investigators found five IEDs in a backpack near a train station in Elizabeth, New Jersey. While a bomb squad robot was attempting to disarm one of those devices, it went off. No one was injured in that denotation.
Officials have no reason to be believe Rahami is part of a larger terrorism cell or network.