MANHATTAN — Within minutes of the Chelsea explosion Saturday night, NYPD and FBI investigators began combing social media for clues about who might be responsible for the blast that injured nearly 30 people, as well as for planting a second device four blocks away.
They quickly found a host of rants and chatter online, including a carefully crafted claim of responsibility that was posted on Tumblr shortly after midnight Sunday. The post has since been taken down.
Sources say the claim highlights the daily difficulty law enforcement faces in separating fact from fiction on the web as investigators try to identify criminals and combat terrorism, and where to best use its resources.
The author of the one-page missive said he left the bombs to highlight social injustices and prejudice in America, and that he would continue to plant more explosives to fulfill his mission to become an agent for change, although he said he does not "know exactly how I feel about taking human lives."
Investigators on Sunday were trying to track down the author of the post to determine if he was a hoaxer, someone trying to capitalize on a tragedy, or if he was, in fact, the suspect responsible.
“It is certainly an investigative lead that we are taking, like all leads, very seriously,” a law enforcement source explained. "It was posted not long after the incident, is not rambling, and is pointed as though it may have been written before and revised after."
Still, the source said it was unclear if the author was actually involved in the Chelsea blast.
"We won't know until we run it down and know we no longer have to," the source concluded.
At a press conference Sunday afternoon at Police Headquarters, new NYPD Commissioner James O’Neill said investigators had no hard evidence yet of what motivated the bomber and that the probe was in its early stages.
But he noted that “a political or social motivation” could be a factor rather than someone inspired by international terrorist organization.
Meanwhile, the NYPD bomb squad continued the painstaking task of collecting and examining remnants of the device that exploded inside a dumpster on W. 23rd Street on Saturday evening, rocking the neighborhood and sending shrapnel throughout the block.
Recovered parts at the bomb site could contain forensic materials that could help lead to the bomb maker’s identity, or at least to where the parts were made, or purchased.
The unexploded device recovered at West 27th Street could also provide a small trove of evidence, and it was being meticulously examined late Sunday by the NYPD bomb squad at its range in Rodman’s Neck, The Bronx.
They have also sent the cellphone attached to the second device to the FBI's offices in Quantico, Virginia, seeking other clues to pursue.