1. A man was arrested and charged in a weeklong pipe bomb campaign targeting critics of President Trump.

Federal authorities identified the suspect as Cesar Sayoc Jr., a 56-year-old Florida man who is an outspoken supporter of Mr. Trump. Records show that he has a long criminal history and ties to New York. Here’s what we know about him. Above, an F.B.I. agent examining a van in Plantation, Fla.

His arrest came even as four more bombs were found around the country, including ones addressed to Senators Cory Booker of New Jersey and Kamala Harris of California.