From the story....
Since the bomb remained intact, it allowed investigators to examine the cellphone attached to the bomb intact and discover that it was connected to the family of Rahami.
From there, they were able to identify pictures on social media of Rahami’s family and of him, and they matched one of his photos to surveillance footage captured in Manhattan.
Unbelievable that Rahami didn’t even bother to try to cover his tracks in the event that the bomb didn’t go off....
When you’re hot for celestial virgins, who bothers with that kind of thing?