There’s no particular harm in passing off glitzy gimmickry as a revealing documentary when the subject is a fashion designer or rock ‘n’ roll band. But to take a superficial, flash-and-dash approach to the aftermath of a suicide bombing is inexcusable.

The Canadian film “Diameter of a Bomb” purports to be an in-depth examination of the events surrounding the June 2002 attack on a Jerusalem bus that killed 19 Israelis. In fact, it barely takes a paragraph (which I’ll duly provide) to relate the fresh insights provided by this glossy waste of time.

“Diameter of a Bomb” screens twice in the fourth annual DocFest, the San Francisco Documentary Film Festival.

A conventional chronology leading up to and away from the bombing would provide all the suspense, shock and pathos anyone could ask for. But that was either considered too old school or the filmmakers didn’t have enough material. They opted instead to chop, churn and recycle their footage in a couple of different ways.

The first 15 minutes or so consist of a jittery montage that aspires to pull off the queasy trick of playing up the sensationalism of a bloody event while evoking individual loss. Footage of the devastated bus and adjacent row of bodies is intercut with slivers of interviews with the husbands or mothers of a few of the victims.

Then the filmmakers retrace their steps in slightly greater detail. We hear more from the families about the morning of the bombing, their last goodbyes and the bits of chance that placed their loved ones on that bus. We also meet the bomber’s family.

One young Israeli recalls how the bus was so crowded as it approached his stop that everyone couldn’t get on. He chivalrously let a lovely teenage girl board ahead of him, only to have the driver close the doors in his face.

Another fellow recalls his roommate trying to rouse him that morning. Had he gotten up, he notes, his friend would have been delayed and wouldn’t have died on the doomed bus.

These snatch-and-grab interviews are tossed with aerial shots, slow-motion bits and spiffy graphics, and the entire hopscotch edit is underlaid with a pulsing, jitters-inducing score. This kind of soundtrack is employed increasingly in documentaries, as a crude method of producing continuous low-grade tension.

In this case, one gets the sense that the filmmakers don’t trust the subject matter to hold our interest. It seems rather clear that a documentary maker who can’t generate drama from a suicide bombing should find another line of work.

As previously mentioned, there are two or three fragments of useful information half-submerged in the movie. I did not know, for example, that a group of religious Jews, unaffiliated with the police or government, sends a few people to every attack scene to collect blood, bone and tissue for burial with the body. They use spatulas, sponges and lots of paper (to absorb the blood).

Also, the bomber in this case was not the stereotypical poor young militant, but a middle-class man working on his master’s degree. His talents included painting and calligraphy.

Make of that what you will, for ultimately there are no lessons to be gleaned or geopolitical updates to be taken from this slick hodgepodge.

We already knew that the death of a young person is horrible beyond comprehension, and that their family never fully acclimates to their loss.

“Diameter of a Bomb” screens 9 p.m. Friday, May 12 at the Roxie Film Center,

3117 16th St. at Valencia, S.F., and at 9 p.m. Monday, May 15 a few doors down at the Little Roxie. Tickets: $10 in advance at www.sfindie.com or at the theater the day of the show.

J. covers our community better than any other source and provides news you can't find elsewhere. Support local Jewish journalism and give to J. today. Your donation will help J. survive and thrive!

Michael Fox is a longtime film journalist and critic, and a member of the San Francisco Bay Area Film Critics Circle. He teaches documentary classes at the Osher Lifelong Learning Institute programs at U.C. Berkeley and S.F. State. In 2015, the San Francisco Film Society added Fox to Essential SF, its ongoing compendium of the Bay Area film community's most vital figures and institutions.