Worldy Armand, 39, was taken into custody after officers on patrol in the area concluded that he matched the description of the suspect, according to Boston police.
Armand, who had an active arrest warrant for receiving stolen property, will be arraigned in Boston Municipal Court for willful and malicious burning, police said.
“What happened in the early hours of this morning to the ballot dropbox in Copley Square is a disgrace to democracy, a disrespect to the voters fulfilling their civic duty, and a crime,” said a joint statement from Boston Mayor Marty Walsh (D) and Massachusetts Secretary of State William Galvin (D).
The incident is at least the second alleged arson attack this month on ballot drop boxes, which have emerged as a popular option for the record numbers of Americans voting remotely to avoid polling places during the coronavirus pandemic. In Southern California last week, as many as 100 ballots were endangered when a drop box was set on fire.
The Boston incident began around 4 a.m. Sunday, police said, when firefighters responded to reports of smoke billowing out of a drop box near Copley Square.
After firefighters extinguished the blaze, elections officials examined the box. They found about 122 ballots inside and determined that 35 of them were too illegible from the damage to process, the Boston Election Department said.
Police later reviewed surveillance footage and released still images of a man approaching the box with what appeared to be a flaming object in his hand. The FBI is also probing the fire, noting in a statement that “it is a top priority of our offices to help maintain the integrity of the election process in Massachusetts by aggressively enforcing federal election laws.”
Boston election officials are asking anyone who used the box after around 2:30 p.m. Saturday to contact them to get a new ballot. The Copley Square box is undamaged and still open for ballot drops, the Boston Election Department said, noting that all boxes are “under 24-hour surveillance and emptied on a daily basis.”
With the pandemic still raging nationwide, drop boxes have taken on an outsize role in the presidential contest. Election officials have pitched them as a safe alternative to polling places and a more reliable means of delivery than the U.S. Postal Service, which has been hamstrung by delays under the controversial policies of Postmaster General Louis DeJoy.
But the Trump campaign has sued over their use, and critics have argued that the drop boxes will confuse voters or not be safe enough from tampering. In California, meanwhile, state officials are locked in a legal battle with Republicans over dozens of unofficial ballot drop boxes set up at gun shops, churches and elsewhere.
In Boston, authorities urged voters not to let the alleged arson damage their trust in the voting system.
“We ask voters not to be intimidated by this bad act, and remain committed to making their voices heard in this and every election,” Walsh and Galvin said in their joint statement.