Pray that investigators, now led by the U.S. Attorney’s Office in Boston, quickly figure out who set fires at Jewish centers in Arlington and Needham and bring that person to justice. Though it’s hard to know the motivation of an unidentified arsonist, given the circumstances it’s a safe bet their intent was to intimidate, if not injure. And, to be sure, their targets in all instances were families.

The first fire was set Saturday, May 11, at the Chabad Center for Jewish Life Arlington-Belmont, where Rabbi Avi Bukiet lives with his wife and children. Another fire was set there five days later. In both cases, the fires were caught quickly and damage was minimal. Shortly after the second fire was set at the Arlington center, there was a third, this time at Chabad Jewish Center in Needham.

Both buildings are locations for worship and study. They are also homes. Rabbi Mendy Krinsky lives at the Needham center with his wife, Chanie, and their children. In a Facebook post, she described smelling the fire before anyone else, her husband grabbing an extinguisher to put it out before the smoke alarms went off, and rousing her children and putting them in the car. “Somebody out there wants to hurt us. Just because we exist. And that is frightening,” she wrote. “Hate can’t be reasoned with. Hate just needs to be eradicated. A little bit of light dispels a lot of darkness.”

Coincidentally enough, the fires were set in Arlington and Needham shortly after the Anti-Defamation League released its annual report on anti-Semitic incidents around the country. The group tallied 1,879 cases of harassment, vandalism and assault targeting Jews the prior year, from swastikas scrawled on street signs to a shooting spree at the Tree of Life synagogue in Pittsburgh that killed 11 people.

Of the cases catalogued nationally, 144 were in Massachusetts, 10 in New Hampshire. Those numbers were down from prior years but still represent a significant increase from three, six and nine years earlier.

Numbers are one thing — a string of arson makes quite real a disturbing trend that can only be altered with vigilance, swift justice, and in the words of Chanie Krinsky, more light to dispel the darkness.