But authorities quickly launched a wide-ranging investigation into the devices that targeted multiple Democrats - including two former presidents - and foes of President Donald Trump's administration ahead of the November 6 midterm elections.
"The Secret Service has initiated a full scope criminal investigation that will leverage all available federal, state, and local resources to determine the source of the packages and identify those responsible", the agency said in a statement. At the time, they appeared not to know it was tied to the suspicious package sent to their building.
And on the other side of the political spectrum, Republican congressman and House majority whip Steve Scalise was one of several people wounded in June 2017 by a rifle-toting left-wing activist who died in the ensuing shootout with police.
CNN's Jim Sciutto and Poppy Harlow were on the air shortly after 10 a.m., conducting a live interview about the devices sent to politicians when the whooping sound of an alarm went off.
"There's a number of devices and there's a pattern apparently with them", he said. A law enforcement official told CNN that the initial examination of all of the devices shows them to be constructed similarly.
The suspicious devices are either at the FBI Laboratory in Quantico, Va., or on their way there now, authorities say, where the FBI's specialists will reach conclusions as they continue their examinations. And they came as authorities were intercepting more suspicious packages addressed to actor Robert De Niro, another vocal Trump critic, and former Vice President Joe Biden, who has also criticized Trump.
Brennan is actually a contracted analyst at NBC News, but the package was sent to the Time Warner Center in NY, where CNN's offices are. He called the bomb squad.
The U.S. Secret Service intercepted a bomb that was addressed to Hillary Clinton at the Chappaqua, New York, home she shares with former President Bill Clinton, and another that was sent to former President Obama at his home with Michelle Obama in Washington.
Like earlier targets, both Biden and De Niro have been sharply critical of Trump.
"Those engaged in the political arena must stop treating political opponents as being morally defective", Trump said, possibly referring to his critics rather than himself.
NYPD responded to a suspicious device discovered at the Time Warner Center, where CNN is based, in New York City.
The first crude bomb to be discovered was delivered Monday to the suburban NY compound of George Soros, a liberal billionaire and major contributor to Democratic causes.
Soros' Open Society Foundations has been a financial supporter of NPR.
The FBI said a package, "similar in appearance to the others" found this week, was addressed to Booker and located in Florida.
"Republicans just don't do this kind of thing", said Rush Limbaugh, the conservative talk radio host Wednesday morning.
Wasserman Schultz's office was evacuated when the envelope arrived on Wednesday.
He seems to be hellbent on a strategy of creating as much fear and division as possible in the country as the means of ensuring victory for his Republican Party in the midterm elections on November 6.
"Let's get along", he said. "There's no reason to be afraid".
Police intercepted what appeared to be a live explosive device and an envelope containing white powder at the Time Warner Center, where the CNN newsroom in NY is based, Police Commissioner James O'Neill told the news conference. At least one contained projectiles, including shards of glass, a law enforcement official told CNN. That isn't enough, he explained. The devices are rudimentary but functional. "I'm not seeing that second power source".
According to the police report, Sayoc called Florida Power and Light, a power company, in August 2002 and threatened to blow them up. Campaign chairman Brad Parscale said that it was an automated message and that the campaign does not condone violence against anyone who works for the network.
The politics belied the life-and-death nature of the growing list of bombing targets in New York, Delaware, Washington, D.C., Florida and California.
A statement was released by White House Press Secretary Sarah Huckabee Sanders on Wednesday condemning the attempted attacks on the Mr Obama and the Clintons. Police alerted the FBI and the Bureau of Alcohol, Firearms and Explosives.
"This investigation is of the highest priority for the FBI", Wray said.