The FBI has made an arrest in connection with the nationwide bombing campaign against outspoken critics of President Trump. It is a significant breakthrough in a case that has gripped the country in the days leading up to the midterm elections.

The suspect is Cesar Sayoc, 56, of Aventura, Fla.

Sayoc, a registered Republican, has a lengthy criminal history in Florida dating back to 1991 that includes felony theft, drug and fraud charges, as well as being arrested and accused of threatening to use a bomb, public records show.

His criminal record from the Florida Department of Law Enforcement indicates that at the time of his last arrest in 2015, he was 5-foot-11 and 215 pounds. He has brown eyes, black hair and a scar on his left arm, the records said, and was born in New York. The records listed Mr. Sayoc’s occupation as “manager.”

FLASH: Cesar Sayoc, 56, pictured in this booking photo from an arrest, via @browardsheriff pic.twitter.com/zUSXxPlOyZ — Myles Miller (@MylesMill) October 26, 2018

The arrest came only hours after the mysterious spate of pipe bombs spread further as federal authorities said this morning that they had found two more of the explosive devices: one addressed to Senator Cory Booker and the other to James Clapper Jr., the former director of national intelligence.

Although no formal charges have been filed yet, two of the law enforcement officials said there was a high likelihood that Sayoc would be prosecuted at least in part in Federal District Court in Manhattan.

The F.B.I.’s New York office has been leading the investigation and five of the bombs sent this week fall under the jurisdiction of the United States attorney’s office in Manhattan.

The package addressed to Clapper was meant to be delivered to the New York offices of CNN, where he works as an analyst, but was intercepted at a mail facility in Midtown Manhattan, police officials in New York City said.

The package addressed to Booker, a New Jersey Democrat, was found in Florida, which two people briefed on the matter have said has become a focus of the intense, nationwide investigation into the bombs.

Also Friday morning, Florida news organizations reported that the authorities had surrounded a white van with Trump stickers on it.

All together, 12 crude explosive devices have been found since Monday, sent through the mail to a host of Democrats and other prominent figures who have been among Trump’s most vocal detractors.

The packages — virtually identical in plain manila envelopes — have been addressed to former President Barack Obama; former Vice President Joe Biden; former Secretary of State Hillary Clinton; Representative Maxine Waters of California; former Attorney General Eric Holder; John Brennan, a former C.I.A. director, the actor Robert De Niro; and George Soros, the billionaire Democratic donor.