Plantation, Florida – Police have arrested a male suspect in Florida in connection with a series of possible explosive devices mailed to prominent Democrats across the U.S.

Law enforcement officials have identified the suspect as 56-year-old Cesar Sayoc, NBC News reported.

Sayoc was arrested in a parking lot in Plantation, NBC News reported.

Investigators also surrounded a white van plastered with bumper stickers and decals believed to be connected to the suspect, CNN aerial footage showed.

The van was wrapped in a blue tarp before it was loaded onto a truck bed and hauled away.

According to a law enforcement source, he has previously been arrested for terroristic threats, FOX News reported.

He is a former resident of New York, but has been residing in Aventura, Florida, the source said.

The Department of Justice has scheduled a press conference for 2:30 p.m. ET, FOX News reported.

Authorities have now found a total of 12 suspicious packages, with the addition of one for U.S. Senator Cory Booker (D-New Jersey) and one for former Director of National Intelligence James Clapper found on Friday morning.

Authorities recovered a package addressed to Booker, similar in appearance to the 10 others that contained pipe bomb-like materials, inside a postal facility near Opa-locka, Florida.

That postal facility has become a focal point in to the federal investigation as it appears several of the packages may have passed through the facility, sources told WABC.

The Miami-Dade bomb squad conducted a sweep of the facility at the request of federal law enforcement.

The package addressed to Clapper was discovered on Friday morning at the West 52nd street post office in Manhattan, and addressed to CNN at the Time Warner Center, according to WCBS.

It was the second package containing bomb-like materials to be sent to CNN this week.

The first was addressed to former CIA Director John Brennan, and it caused “CNN Newsroom” to cut its live news feed as reporters and staff evacuated the building on Wednesday morning.

The New York Police Department shut down several blocks around the affected area while they investigated, USA Today reported.

Bomb-like devices were also sent to Democratic billionaire donor George Soros, former Secretary of State Hillary Clinton, former President Barack Obama, former Attorney General Eric Holder, U.S. Representative Maxine Waters (D-California), actor Robert De Niro, and former Vice President Joe Biden.

Biden received two of the crude pipe bombs, but both packages were intercepted by a post office in Wilmington, Delaware, WABC reported.

The return address on at least one of the packages to Biden was U.S. Representative Debbie Wasserman Schultz, whose name appeared as the sender on several of the packages sent.

On Wednesday, Wasserman Schultz received the package intended for Holder at her Sunrise office because of a bad address.

Law enforcement are investigating the bombs as a domestic terror threat, WJW reported.

The bombs have been taken to the FBI lab in Quantico for investigation.

Sources have said officials are puzzled by the fact that none of the pipe bomb-like devices have detonated, raising questions about both the motives and the skill level of the bombmaker, WJW reported.

There are two theories about what the FBI has referred to as “potentially-destructive devices” – either the bombs were poorly constructed, or they were never intended to explode.

WJW reported that authorities considered the contents of the packages potentially destructive because of the presence of what is believed to be pyrotechnic powder, although nothing exploded during transport.

The lack of a triggering mechanism on the devices also suggested they were never meant to actually detonate, according to outside explosives experts.

“Whoever is doing this is just trying to elicit a fear or disrupt something,” Tripwire Operations Group Founder Ryan Morris said.

His company provides explosives training to police and military, WJW reported.

Morris examined images of the devices sent to Soros and to CNN’s New York offices, and commented “there are a multitude of more sophisticated methodologies that would have worked if they really wanted this to work.”

The devices are made up of common components, which makes investigation more difficult, WJW reported.

New York Police Commissioner James O’Neill said it was unclear if there were still more bombs waiting to be delivered.

“But with the postal services that are here, we’re doing our best to make sure that if there are any out there we identify them quickly,” Commissioner O’Neill said.

In response to the threat, New York Governor Andrew Cuomo announced late Wednesday night that he was bringing in the National Guard to assist with security, WABC reported.

“Out of an abundance of caution, I am deploying 100 additional National Guard soldiers and directing State law enforcement to double security at vital assets across New York, including LaGuardia and JFK, mass transit systems, and bridges and tunnels,” the governor said.