It bears the same stamps and labelling as one suspicious package intercepted Wednesday, when the bomber sent pipe bombs to the Clintons, Barack Obama, and CNN's NY offices, as well as two devices to former vice-president Joe Biden.
Just two days earlier, CNN's offices in NY were evacuated when the package for Brennan, addressed to him at the network, was found in the mailroom.
A suspicious package containing a similar device, addressed to Brennan, was found in the mailroom of the Time Warner Center, forcing the evacuation of the building which houses CNN's NY headquarters.
Federal, state and local investigators in New York, Washington, Florida and Los Angeles were involved in the widening case, which has not resulted in any injuries but has sent a shock wave through the nation's political and media establishments.
On Wednesday, we learned that explosive devices were mailed to the Obamas, the Clintons, and CNN, a day after George Soros also received a crude pipe bomb in the mail. The common thread among them was obvious: critical words for Donald Trump and frequent, harsher criticism in return. Each listed Debbie Wasserman Schultz, former chairwoman of the Democratic National Committee, as the sender, including misspellings of her last name, the Federal Bureau of Investigation said.
"We will prosecute them, him, her, whoever it may be, to the fullest extent of the law", he said at a White House event.
Wray declined to say whether the devices could have detonated, saying that investigators are "still trying to determine whether or not they were functional".
That person, who has a background in law enforcement, recalled seeing a similar package at the film center mailroom earlier and reported it to police.
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.
The New York Police Department says Thursday's report involves the Tribeca neighborhood in Manhattan.
Specifically, he said, the X-ray shows only one set of batteries for the timer. An official said it was suspected to have been delivered earlier this week.
"It does remain possible that further packages have been or could be mailed", William Sweeney, assistant director of the Federal Bureau of Investigation, told an afternoon news conference in NY. Mainstream Media must clean up its act. One target of the suspicious devices, former CIA Director John Brennan, hit back at Trump on Twitter on Thursday.
Republican lawmakers followed the White House in issuing condemnations.
The U.S. Secret Service intercepted the 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 Obama at his home in Washington. Each was affixed with a computer-printed address label and six "forever" postage stamps, the agency said.