Who Could Be Behind Serial Pipe Bombings?

Who is the bomber that sent explosive devices to high profile Democrats around the country? After explosive devices were sent to Hillary Clinton, Barack Obama, George Soros, CNN and Eric Holder, among 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 says the bomber carefully planned every detail.