Improvised explosive devices have been found in four different locations in New Jersey and New York in the span of less than two days. The first bomb detonated in New Jersey's Seaside Park on Sept. 17, blowing a hole in a garbage can positioned near the first mile marker of a 5K fun run for the U.S. Marines. The race was scheduled to begin at 9:30 a.m., but it was delayed by registration issues. Had the run started on time, it is likely that some participants would have been injured in the explosion, which occurred at 9:35 a.m. According to U.S. officials, two similar devices were found in the same trashcan as the pipe bomb that detonated, but they failed to go off when the third device was triggered with a cellphone.
A cellphone was likewise used to set off another bomb at 135 W. 23rd St. in Manhattan about 11 hours later. The explosion injured some 29 people in New York's Chelsea neighborhood; images and eyewitness accounts suggest that many of the injuries were small puncture wounds caused by flying debris. Some of the victims were hospitalized, though all were released by the following day.
The second bomb was far more powerful than the first. The New Jersey device blew a hole in the bottom of a small plastic waste bin, while the Chelsea explosion crumpled a steel waste container. Investigators later confirmed that the Chelsea device was a pressure cooker packed with shrapnel and an explosive compound of aluminum nitrate and aluminum powder commercially known as Tannerite. Two hours later, police officers found a similar bomb four blocks away on 27th St., but it did not detonate. A homeless man found a suspicious package concealed in a trash can at a train station in Elizabeth, New Jersey, not long after. Police cordoned off the area and began investigating the bag with a robot. Though they unintentionally detonated one of the devices hidden inside, they managed to recover four unexploded bombs from the bag.
Authorities believe all of the bombs were made by the same person or cell. By the afternoon of Sept. 18, police had identified several persons of interest from surveillance video of the scenes and from the pressure-cooker device. That evening, FBI agents stopped a vehicle carrying five people on New York's Belt Parkway under the Verrazano-Narrows Bridge. Though the agency stressed that it has not arrested the vehicle's occupants, it is questioning them, and on Sept. 19 officials arrested their primary suspect, 28-year-old Ahmad Khan Rahami, after he got into a shootout with police. Rahami, who was wounded in the encounter but is expected to survive, is an ethnic Afghan and naturalized U.S. citizen whose role in the attacks is not yet clear. However, statements by authorities suggest he may be the bombmaker. According to two U.S. officials cited by Reuters, Rahami is not in any U.S. counterterrorism databases and two additional suspects are being sought in the investigation. Though it is still too early to assess motives or responsibility for the attacks, it is worth noting that the Islamic State-linked Amaq news outlet quickly claimed credit for a stabbing in Minnesota on Sept. 18. The group has not, however, mentioned the New Jersey or New York attacks, which casts doubt on the possibility of a connection between the two. That said, the perpetrators could have been inspired by the Islamic State or al Qaeda, if not both.
Based on the attacks, the perpetrators do not appear to be highly experienced. Only two of the bombs seem to have detonated as planned, while the other eight either malfunctioned or were recovered before they could be set off. The placement of the bombs is also revealing. The targets the attackers chose were extremely soft and likely required little surveillance prior to placing the devices. The Seaside Park pipe bomb was almost certainly intended to target the widely publicized Marine Corps race, since the Marines are an obvious symbol of U.S. military strength. The New York devices, by comparison, had much less defined targets. The bombs in Elizabeth, meanwhile, clearly targeted rail transportation, but even then the trashcan they were placed in would have minimized the damage done to the station's infrastructure. (Hiding explosives in garbage bins is less effective than putting them in backpacks or suitcases closer to the intended victims, but it also carries fewer risks of being caught.) Together, these factors suggest that the attackers prioritized avoiding capture over inflicting maximum casualties, resulting in attacks that were far more harmful psychologically than physically. Had all of the bombs hit their intended targets, the death toll could have been much higher. But proficiency comes with practice, and that is difficult to get in the current U.S. security environment, where there is a high probability of being caught.