I didn't expect Dzhokhar Tsarnaev to be sentenced to death - but then, living in Boston for so many years, I would never have expected anyone to bomb the annual marathon.
I used to live on "heartbreak hill" - a cruelly long incline before the runners got to the top in Newton, and could look down on the city and the eventual finishing line mercifully downhill, below them. With my children we'd hold out paper cups of water, and urge them on - especially the older ones, doing it for charity - hoping they'd make it.
For in a way they were doing it for us, too: the non-runners who admired their spirit. Then, later, I moved to Cambridge - where Tsarnaev lived and went to high school. It's a suburb - but a pretty pricey one, just across the river from Boston, connected by a slew of pedestrian, subway and road bridges, and with MIT and Harvard as its pearls.
In the autumn, they hold what they call the Head of the Charles - said to be the largest two-day rowing event in the world. There, too, the banks of the river are thronged by hundreds of thousands of spectators, well-wishers and supporters. People of all ages, especially children.
Why choose such a family event to make a religious statement? Why choose it, moreover, to be in your own community: one that had given you asylum, education, a chance to succeed in relative safety and freedom? In the days and months that have followed the backpack-bombings I, like millions who live in Boston and America's north-east, have puzzled over that.
The trial of Tsarnaev - who ran away from the mayhem he had caused and then murdered a policeman in cold blood - has not really offered a credible explanation.
The defence team decided early on not to contest guilt, but to try to pin the blame on his older, more ideologically motivated brother, Tamerlan, who died when Dzhokhar ran over his bleeding body in a shoot-out in Cambridge.
Clearly, the defence didn't succeed - as perhaps was inevitable when they decided not to put Dzhokhar on the stand to explain himself, but to plead for him. Death by lethal injection was the jury's verdict on Friday.
Will he be put to death? The statistics suggest he won't, at least for a very long time - perhaps 10 years - while appeals are heard. Some future president might commute the sentence, too.
But though it seems harsh for one so young - Tsarnaev was 19 when he exploded the bombs - and almost out of character in a state like Massachusetts, where the death penalty was dropped so many decades ago - the verdict will at least bring a kind of closure to one of the saddest episodes in recent Boston history.
In the mid-Seventies the city suffered serious civil disorder, verging on insurrection, during enforced desegregation known as the "busing scandal". The city and state of Massachusetts overcame that dark chapter, however, and its public universities (one of which Dzhokar was attending on a scholarship) are not only fully integrated but are now ranked in the top 50 in America.
Thanks in part to this trial-by-fire, Boston became a modern immigrant city with a proud public ethic - the first to introduce comprehensive health coverage, and with an Italian-American mayor re-elected five times between 1993 and 2014.
"Boston Strong," the slogan invented after the marathon bombings, was an immensely positive, life-affirming response under Mayor Thomas Menino's leadership.
Certainly what moved me most as a resident was how the local media focused far less on the perhaps unanswerable questions of agency and responsibility for mass murder than on the trials facing the survivors: those among the 280 injured with shattered limbs, lost eyesight, battered brains. The stories of their courage - their determination to look ahead, and recover - made the whole question of justice-as-vengeance somehow irrelevant.
Until the day of judgment, that is, two years and one month since the Tsarnaevs struck at the very foundation of Bostonian civil order and collective goodwill.
Doubtless there will be much hand-wringing and discussion of the verdict - just as there has been over recent cases of police arrests, brutality and even killings from Detroit to Baltimore.
However my guess is that in this case there will be few tears shed for the ingrate from Chechnya. Not because the people of Boston are bloodthirsty, but the reverse.
Because Dzhokar Tsarnaev, like his brother, so deliberately targeted innocents: women and children especially, standing near the finishing line as the runners - most of them running for charity and as a test of personal willpower - approached their goal, beneath the flags of many nations hanging in the springtime breeze on Boylston Street that day.
If it comes, his fate will come to us to seem both merited and insignificant beside the grief of the families of those who died - and the ongoing, daily courage of the maimed and injured who survived.
Nigel Hamilton is a senior fellow at McCormack Graduate School, University of Massachusetts Boston