The legal system has always had one set of procedures and consequences for the ruling class, and a different set for everyone else. This observation proves to be as accurate today as it was 400 years ago in a groundbreaking trial in Rome, recreated in “It’s True, It’s True, It’s True” at Marin Theatre through May 4.

In 1612, teenage Baroque painter Artemisia Gentileschi actually had the audacity to bring charges of rape against her mentor, Agostino Tassi, an extremely well-connected artist who was not merely a member of the Italian elite but was the pope’s court painter.

After a gut-wrenching trial that included torture of the plaintiff, Tassi was ultimately found guilty and received a slap-on-the-wrist sentence of a few days’ exile from Rome. His victim went on to become an esteemed pioneer of women in the art world.

Tassi’s trial is portrayed as a punk-rock extravaganza in the compact Sali Lieberman Stage at Mill Valley’s Marin Theatre, a venue chosen to approximate the claustrophobic courtroom of the original event.

The play was pieced together by British playwrights Ellice Stevens and Billy Barrett from fragments of ancient Roman manuscripts.

Contemporary punk music and garish costumes (Pamela Rodriguez-Montero, costume designer) contribute much to the play’s themes of indignation and anger.

Bare-bones staging with only a few props likewise adds to the ersatz courtroom’s oppressive atmosphere, where a banner inscribed “La legge è uguale per tutti” (“Equal justice for all”) is phony reassurance from officialdom, clearly little more than a hollow marketing slogan.

Director Rebecca Wear gets the utmost from her four-member all-female cast, most in multiple roles. Alicia M. P. Nelson is excellent as the haughty judge, whose disdain is countered by the sincerity and conviction of Emily Anderson as Gentileschi.

Maggie Mason puts in a powerful performance as the self-righteous Tassi, who brings in friends and neighbors to damage Gentileschi’s reputation and to dispute her assertions of virginity prior to the rape. San Francisco Mime Troupe member Keiko Shimosato Carreiro is tremendous in various such roles.

She’s also a compelling drummer, as is Nelson. Anderson’s quite good with her few moments on guitar.

Modern audiences may be shocked to learn that in 17th-century Italy, plaintiffs could be required to testify under torture to prove the veracity of their claims. Gentileschi cries pitifully as she endures the pain, but she does not relent.

The legal system at the time also permitted defendants’ direct confrontation with their accusers, rather than intervention by lawyers.

We have made some progress in the ensuing years since Tassi was convicted, but we have to ask how much in view of the preferential treatment given repeat offenders such as Harvey Weinstein or the current occupant of the White House.

Projections of Gentileschi’s paintings would add enormously to this show — not just to its visual impact, but to the audience’s understanding of her importance to the history of art, and to the general advancement of women in Western culture.

Visual reinforcements are glaringly absent. The only such reference is a brief reenactment of one famous painting.

The play’s message is both a downer and an inspiration — a downer, of course, in that injustice is still prevalent worldwide, but an inspiration in showing what one highly motivated young woman can achieve against overwhelming opposition.

“It’s True, It’s True, It’s True” isn’t all gloom and doom, however — there are moments of absurd dark comedy done in exaggerated masks of the commedia dell’arte style to remind us that the whole sordid affair really did happen in 1612.

Barry Willis is a member of the American Theatre Critics Association and president of the San Francisco Bay Area Theatre Critics Circle. Contact him barry.m.willis@gmail.com.