The bomb packages have been found in five states - New York, Delaware, Maryland, Florida and California - and the fourth day of the investigation began in the early morning hours when a retired NYPD detective who now works for De Niro saw an image of one of the suspect devices on the news.
Sayoc's arrest Friday was a major breakthrough in the nationwide manhunt following the discovery of explosive devices - none of which detonated - addressed to prominent Democrats and other frequent targets of conservative ire, including former President Barack Obama, former Vice-President Joe Biden, Hillary Clinton and the cable network CNN.
New York City Mayor Bill de Blasio said the packages were "clearly an effort to terrorize people politically, to choose people for political purposes and attack them due to their beliefs".
On Wednesday, the US Secret Service announced they had found similar packages addressed to former first lady Hillary Clinton and former US president Barack Obama.
Suspicious packages have been seized in New York, Washington, D.C., Florida and California.
Last year Republican Congressman Steve Scalise was shot when a gunman opened fire during training for a Congressional baseball game in Washington. No matter how much he denies responsibility, the rhetoric of President Trump and his supporters carries the blame for the coordinated mailing of pipe bombs to Democratic political officials and other public figures. "We're going to find out what the latest is here and we're going to be right back".
Former CIA director John Brennan, who was sent the pipe bomb care of CNN, assailed Trump for attacking the media.
What is the recent history of violence against United States politicians?
The package had been received in the general mailroom on Wednesday, according to a law enforcement official. "Clean up your act.try to act Presidential".
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The complaint also included details suggesting Sayoc's antipathy toward the people and organizations targeted, including CNN, where one packaged was found and another addressed.
Speaking at an event in Austin, Texas, Mr Brennan called the spate of pipe bombs "an unfortunate turn of events".
But Democratic Senate and House leaders Chuck Schumer of NY and Nancy Pelosi of California said such words "ring hollow" when coming from Mr Trump.
The explosive devices were packed in envelopes with bubble-wrap interiors bearing six stamps and the return address of Florida Rep.
"Any guy who can do a bodyslam, he's my kinda guy", Trump said, mimicking throwing a person on the ground.
Waters, whom the president has denigrated as a "low-IQ individual", reported Wednesday afternoon that she was the target of a suspicious package.
New York Gov. Mario Cuomo was in the midst of the news conference outside the Time Warner Center when he disclosed that his office had also received a suspicious package - news he appeared to learn just moments before when a handler leaned in to give him a message.
In a statement issued today, the Secret Service said it "has intercepted two suspicious packages addressed to Secret Service protectees", who were identified as Mrs Clinton and Mr Obama. The Soros package was believed to have been placed in a mailbox rather than mailed, a separate law enforcement source said.
"The full weight of our government is being deployed to conduct this investigation and bring those responsible for these despicable acts to justice; we will spare no resources or expense in this effort", he told a gathering in the East Room of the White House. One was intercepted at a Los Angeles mail facility.
Authorities have branded the parcel bombs, coming less than two weeks before national elections that could alter the balance of power on Capitol Hill, as an act of terrorism, though they have declined to say whether the devices were built to be functional.