“She wore a black-and-white power suit, double-breasted and very graphic, with big lapels outlined in white. You could say she was making a statement.”

Elizabeth Williams could have been describing an uptown matron smartly turned out for lunch at Sant Ambroeus. But the subject was Gloria Allred, the women’s rights lawyer, whose image she captured in June as Ms. Allred stood in a federal courtroom in Manhattan awaiting sentencing of the singer R. Kelly for racketeering and sex trafficking.

Ms. Williams is a courtroom artist with a canny eye for style. A former fashion illustrator, she is tasked with rendering charged portraits of accused killers, mob chieftains, white collar criminals, sex offenders and, as often, their alleged victims, with a measure of fidelity and journalistic flair.

The cut of a suit, the stony glare, “those are the kinds of things you want to catch,” Ms. Williams said. “Effectively, I’m a visual reporter. I’ve been doing this long enough that I know when something is newsworthy.” (Ms. Williams declined to give her age.)

She was animated, even irreverent, as she conducted a tour of her studio in Midtown, a former beauty spa, its shampoo basins and outsize mirrors having given way long ago to a spartan arrangement of computer stations and work tables.

The walls, in contrast, were covered in strikingly colorful likenesses of Ms. Allred, Martha Stewart and Ghislaine Maxwell, who was tried in November for sex trafficking and procuring underage girls for the financier Jeffrey Epstein. Together the portraits form a veritable rogues’ gallery sketched by Ms. Williams during the course of her decades-long career.

Some of those portraits, and others dating from the early 1980s — the former automobile executive John DeLorean, Mick Jagger, the Russian spy Anna Chapman and Bernard Madoff, among them — were gathered by Ms. Williams and the writer Sue Russell in “The Illustrated Courtroom, 50 Years of Court Art.”

An updated edition published in June highlights Ms. Williams’s illustrations, including those of Harvey Weinstein, Stormy Daniels and Donald Trump, as well as the work of prominent courtroom artists like Bill Robles, Aggie Kenny, Howard Brodie and Richard Tomlinson. Wielding charcoals and brush pens in federal court, where cameras are not allowed, they have documented many of the most sensational trials of the last 100 years.

“Just the presence of these skilled artists meant that something newsworthy was happening in that courtroom,” Linda Fairstein, the lawyer, novelist and former New York prosecutor, wrote in the foreword to the book’s first edition.

Ms. Fairstein went on to argue that in such highly publicized proceedings, “our memory of the moment of triumph or defeat was most likely a vision of the sketch created.”

Ms. Williams’s particular vision is built on a fusion of instinct and experience. Her clients, most often The Associated Press and CNBC, count on her, she knows, to convey the urgency, pageantry and intermittent shocks of live theater.

When jurors at the Maxwell trial were shown an enlarged photograph of Mr. Epstein fondling Ms. Maxwell’s breast with his foot, “she was smiling at the camera like this was a fun thing to do,” Ms. Williams said, her eyes narrowing in a mix of consternation and amusement.

A scholar of human fancies and foibles, she studied fashion illustration at Parsons School of Design and went on to earn a master’s degree from Otis College of Art and Design in San Francisco.

At Parsons, her teachers — including Steven Meisel, the fashion illustrator turned photographer — encouraged her to develop speed, fluidity and the emotional antennae that help her commemorate moments of levity, distress and untrammeled vanity.

She is well aware that dressing for an audience of jurors, journalists and curiosity seekers can be a performance, a bid for sympathy, credibility or, simply, admiring attention. None of this was lost on Martha Stewart, who during her 2004 trial for securities fraud seemed to have consciously styled herself as a portrait of feminine rectitude.

“In her dour tailored suit and schoolmarm shoes with big thick heels, she looked plain, plain, plain,” Ms. Williams said.

Ms. Maxwell, at her trial, wore a balloon-sleeve turtleneck sweater. As Ms. Williams recalled, “It was either heavy wool or cashmere, a $1,000 sweater, I’d guess, that said ‘understated rich lady.’”

During Mr. DeLorean’s 1982 arraignment on drug conspiracy charges, his wife, Christina Ferrara, a former cover girl and television personality, assigned herself a more flamboyant role wearing a royal blue pantsuit with a spray of ruffles at her throat. On another day, “she wore a big puffy gingham dress, with her hair up in a little tie,” Ms. Williams said. “She wore a new dress every day. Her husband was the one on trial, but she was kind of making a play for herself.”

Which brings to mind Anna Sorokin, the society scammer who snared attention in a New York State court in 2019 when she hired a stylist to dress her on various days in a python-patterned shirtdress, a sheer Saint Laurent blouse and Victoria Beckham trousers, and a succession of little white frocks, transforming the courtroom into her personal catwalk.

Such scenes pose challenges no more or less exacting than sketching a fashion show. “The courtroom is more dramatic,” Ms. Williams said, “but in each instance, you’ve got to get an overall sense of design, movement and style, and any kind of specific detail to create a mood.”

There is plenty of pressure, but she likes it that way. “What I’ve learned is that the drawing is not here in my head,” she said. “It happens our there.” She made a sweeping gesture toward the far end of the room. “That’s where your focus must be.”

She works with a brush pen, starting with a series of sketches that isolate her subject’s eyes or the way that she covers her mouth with her fingers, “until finally I understand that face well enough to really start to draw.”

In her practice, she plays by the rules. Among guidelines set out by The Associated Press, “individuals and objects must be pictured as the were in the courtroom.” Also, “No artistic license should be taken with regard to facial expression or personal characteristics of subjects.”

Her work can take an emotional toll. “I’ve seen a lot of disturbing things especially when I’m watching the victims,” she said. During the Maxwell trial, she sketched one young woman, a witness who was not identified by name, covering her anguished features with heavily jeweled fingers.

That image haunts me,” Ms. Williams said. “There is anger, embarrassment — that’s what courtroom are. And always, there’s tension.”

As an antidote to stress and to supplement her income, Ms. Williams has embarked an incongruous, if far cheerier, sideline. As a wedding illustrator, she finds herself sketching portraits of couples sharing moments of affection, intimacy and unconcealed joy.

“Look at these two, the way they look at each other,” she said, pointing out a sketch of newlyweds, pinned to a wall. “They’re so happy, so jovial, these people. And they’re dressed in beautiful clothes. What more can you ask?”

Inevitably, though, she returns to the courtroom. When Ms. Maxwell appeared in court in June to make her sentencing statement, she wore a dun-colored T-shirt and trousers and sober-looking spectacles, her hair parted to show silver roots. Ms. Williams memorialized the scene and, with it, a second portrait of Ms. Maxwell being escorted from lockup in leg shackles.

“It was such a contrast to that day last fall when she strolled into court in a statement sweater,” she said. “What a comedown.”