Worldy Armand was arrested Sunday night on a charge of willful and malicious burning of dozens of ballots inside ballot drop box.
Armand is accused of committing arson outside Boston Public Library in Copley Square at around 4am on Sunday.
Surveillance photos released by police showed a man standing in front of ballot drop box with something burning in his hand.
There were 122 ballots inside the box when it was emptied Sunday morning, and 35 were damaged, of them as many as 10 cannot be counted.
Voters who used that dropbox between Saturday afternoon and 4am Sunday and can't confirm their ballot status online should contact Elections Department.
A man was charged this afternoon with setting a Boston ballot drop box on fire and damaging nearly three dozen ballots.
Worldy Armand, a 39-year-old Boston resident, was taken into custody late Sunday, hours after he started a fire inside a drop box outside the Boston Public Library in the city's Back Bay neighborhood, authorities said. The box contained more than 120 ballots.
Armand was arraigned on Monday in Boston Municipal Court on a charge of willful and malicious burning. A judge ordered a mental health evaluation for the defendant.
'I do not believe that this individual is plotting against our democracy. I think that he is emotionally disturbed,' said Suffolk County District Attorney Rachael Rollins, as WCVB reported.
Armand was arrested after drug control unit officers on patrol saw a man who matched the description of the suspect authorities were looking for in the ballot box fire, police said. Police said he also had an active warrant for receiving stolen property in Ipswich.
Boston Mayor Marty Walsh released a statement, thanking law enforcement officials for swiftly making an arrest.
'From our election workers who are working hard to trace every legible ballot in that drop box, to our firefighters who quickly responded to the fire, and our police officers who launched an immediate investigation, voters can be assured that our first and foremost priority is maintaining the integrity of our elections process,' the statement read. 'We remain committed to making their voices heard in this and every election, and maintaining transparency and trust with voters.'
The FBI had said Sunday that it's investigating. Federal authorities urged members of the public to 'remain vigilant and immediately report any suspicious, election-related activity.'
Massachusetts' elections chief said he has directed local officials to boost security at drop boxes with guards and video surveillance, and to empty the boxes frequently.
Secretary of the Commonwealth William Galvin said in an interview Monday that he is also advising communities to lock their ballot drop boxes on Saturday night, which is Halloween.
'We're concerned that for that period of time, especially after dark, that they could be the object of pranksters or other individuals,' Galvin said.
The fire was started at around 4am in the ballot drop box outside the Boston Public Library in Copley Square, Massachusetts Secretary of the Commonwealth William Galvin's office said.
There were 122 ballots inside the box when it was emptied Sunday morning, and 35 were damaged, of them as many as 10 cannot be counted. The remaining 87 ballots were still legible and able to be processed, Galvin's office said. The box had last been emptied around 2.30pm on Saturday.
In a joint statement, Galvin and Mayor Walsh called it a 'disgrace to democracy, a disrespect to the voters fulfilling their civic duty, and a crime.'
'Our first and foremost priority is maintaining the integrity of our elections process and ensuring transparency and trust with our voters, and any effort to undermine or tamper with that process must be prosecuted to the fullest extent of the law,' they said in the emailed statement. 'We ask voters not to be intimidated by this bad act, and remain committed to making their voices heard in this and every election.'
Boston Police said an arson investigation is underway and released surveillance images of a person near the ballot box outside 700 Boylston Street at that time, urging the public to help identify the individual.
One of the photos shows the suspect standing in front of the ballot drop box holding something burning in his left hand.
'We’re going to insist on prosecuting whoever did this and want them to know they’re going to be apprehended and go to jail,' Galvin said, according to NBC Boston.
Officers called to the scene saw smoke coming out of the box before firefighters managed to extinguish the fire by filling the box with water, police said.
Despite the extensive damage to the internal plastic lining, the drop box at Copley Square is still available for voters to deposit their ballots.
Boston's 17 ballot drop boxes are under 24-hour surveillance and are emptied daily.
The FBI said in a statement announcing their investigation 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.'
Voters can go online to see whether their ballot was processed. Those who used that dropbox between Saturday afternoon and 4am Sunday and can't confirm the status of their ballot online should contact the Boston Elections Department immediately, officials said.
Voters whose ballots were affected can either vote in person or by a replacement ballot that will be mailed to them, officials said. If those voters don't submit a new ballot, 'their original ballot will be hand-counted to the extent possible,' Galvin's office said.
'My immediate concern is to notify every city and town clerk in Massachusetts," Galvin told WCVB. 'I sent out an urgent directive this afternoon to secure ballot drop boxes. If at all possible, have them inside of municipal facilities. If necessary, as we go down the stretch in this election and they need police officers there, that's what they need to do. We'll deal with the compensation issues later.'
It's the second fire reported at a ballot box in the U.S. this month. A fire inside an official Los Angeles County ballot drop box is also being investigated as arson, authorities said last week.
Early voting began last Saturday in Massachusetts, and more than 2 million residents have already cast their ballots in person or by mail.