"He's an individual that was seen lurking around the parking garage between 6:30 in the morning on Monday morning and 7:15," Mark Potter of the Bureau of Alcohol, Tobacco, and Firearms said.
Although initially, authorities reported they were looking for a man dressed in all black clothing, they believe it's the same person seen in these pictures except that he's carrying the black jacket not wearing it.
"So, he matches the general description, he's in the area, we have several witnesses that see that description," Potter said.
A task force of federal state and local investigators are now actively involved in trying to track the man, who placed the device, which authorities previously said was capable of causing serious harm and damage.
"Anytime you have an individual who has the wherewithal or knowledge to construct such a device and the criminal intent, you're dealing with a dangerous individual," Chief Scott Bohn of the West Chester Police Department said.
But, as authorities have tried to zero in on a suspect over the last 3 days, the question of motive, which would seem to play a crucial role in the investigation, remains unanswered.
"We're at the early stages of this, we're trying to identify this individual and maybe we could answer those in a short period of time," Potter said.
Anyone who thinks they have information is being asked to call the ATF hotlines at 215-446-7860 or 888-ATF-BOMB.
Look at the slideshow above to see if you can identify the man.
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