Federal authorities made an arrest on Friday in connection with the nationwide bombing campaign against outspoken critics of President Trump, a significant breakthrough in a case that has gripped the country in the days leading up to the midterm elections.
A law enforcement official identified the suspect as Cesar Sayoc Jr., 56, of Aventura, Fla., just north of Miami. It was not clear whether the authorities were seeking other suspects or if Mr. Sayoc acted alone.
The arrest came even as the crude pipe bombs continued to appear across the country. One, found in Florida, was addressed to Senator Cory Booker, a New Jersey Democrat; another, discovered in a Manhattan post office, was sent to James R. Clapper Jr., a former director of national intelligence; and a third was intercepted before it reached Senator Kamala Harris, a California Democrat.
A fourth bomb, found on Friday in a mail facility in California, was addressed to Tom Steyer, a prominent Democratic donor, a person close to him said.
At a news conference Friday afternoon, Attorney General Jeff Sessions announced that Mr. Sayoc had been charged with five counts, including illegal mailing of explosives and threats against former presidents. The packages included photographs of the intended targets marked with red Xs, according to a criminal complaint.
The officials said they tracked down Mr. Sayoc after finding his fingerprint on one package sent to Representative Maxine Waters, a California Democrat.
Mr. 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.”