After explosive devices were sent to Hillary Clinton, Barack Obama, Joe Biden, George Soros, the New York offices of CNN and others, more packages were sent to Robert De Niro, and two locations where Joe Biden has addresses in Delaware.
The bombs were all shipped in the same envelope with the same stamps and same labels.
Former NYPD Lieutenant Darin Porcher told Inside Edition that the bomber carefully planned every detail, including the color of the envelope.
He said the bomber used a manila envelope because “it is opaque” whereas a white envelope "will have the ability to see inside the envelope.”
Then, there are the stamps: six "forever" stamps per package in two neat rows.
"They usually put more postage than less postage," he said. "He or she does not want the packages returned for insufficient postage."
The envelopes are all sealed with clear packing tape, Porcher said that’s to seal it and to prevent its detection by bomb-sniffing dogs.
The address labels were all printed, but the font is so commonly used that it will not likely be a helpful clue.
Another clue is on the side of the bomb sent to CNN, there's a flag that looks like an ISIS flag at first glance, but it's actually a parody circulating on right wing websites for years. Instead of Arabic letters, the flag says “Get ‘Er Done” in a strange font.
"This strikes me as someone who has an ax to grind against Democrats and Democratic supporters," Porcher said.
The investigation is reportedly now focusing on whether or not the packages were sent from Florida.