The Washington Post building at 1301 K St. NW. (John McDonnell/The Washington Post)

The Washington Post has dismissed a reporter for inadequately attributing material and closely parroting sentences from other publications in articles based on outside news sources.

The reporter, Marwa Eltagouri, 26, was let go last week before completing the newsroom’s mandatory nine-month probationary period for new employees.

The Post’s editors found that she used without proper attribution reporting by at least a dozen other news organizations in articles she wrote since being hired in October. The sources included the New York Times, the Sacramento Bee, CNN, the Orlando Sentinel, the Oregonian, Canadian Broadcasting Corp. and the McDonough County Voice, a daily paper based in Macomb, Ill.

The Post did not characterize Eltagouri’s actions as plagiarism, which is a gross breach of journalistic ethics and often warrants dismissal.

Instead, Eltagouri’s conduct appears to have fallen into a grayer area involving “aggregation,” the rewriting of news stories published by others. The practice has become common among many news organizations as they seek to compete for readers on the internet.

Journalists engaged in aggregation are obligated to attribute basic facts, quotes and assertions to their source; any rephrased prose must also be attributed. The rules for structuring an aggregated story are generally murkier.

Eltagouri appears to have mimicked too closely the structure of the news stories she was aggregating. She also failed to attribute various facts from those articles, potentially leaving a reader with the impression that she had gathered the information herself. And her wording, at times, closely resembled — although it didn’t precisely copy — the source article.

“I sincerely regret any missteps made while aggregating these stories,” Eltagouri said Wednesday. “I take The Post’s high ethical standards seriously and remain deeply dedicated to journalism, its public service mission and the principles every reporter must follow.”

In a story published May 22 about a California man who posed as a federal agent, Eltagouri began her article this way: “Those who knew 26-year-old Matthew Johnston never questioned whether he was actually an Immigration and Customs Enforcement agent. Johnston, after all, wore a uniform. His tactical vest bore ‘ICE’ and ‘Federal Agent’ patches, and he carried an ICE Counter Terrorist Unit and Gang Task Force identification card. On Facebook, he described his job as ‘fugitive apprehension’ for the Department of Homeland Security.”

The article was based on a Sacramento Bee article published earlier the same day. It began, “Everyone in his life — his friends, family, girlfriend and ex-wife — believed Matthew Johnston, 26, was an Immigration and Customs Enforcement agent. . . . He wore ICE badges and uniforms. He used blue and red police lights on his car. He had a tactical vest that said ‘federal agent.’ Johnston described his job on Facebook as ‘fugitive apprehension’ for the Department of Homeland Security, which includes ICE.”

The Post article contains other phrases echoing the Bee story. “Johnston boasted about being an ICE agent to the employees and patrons of a nearby strip club, Deja Vu Showgirls, in Industry, Calif., prosecutors said,” Eltagouri wrote.

The Bee’s story said, “Johnston also bragged that he was an ICE agent to patrons and workers at Déjà Vu Showgirls, a strip club in Industry, California, prosecutors said.”

Editors found a dozen stories written by Eltagouri from late December to last month that contained unattributed material. These stories now carry a notification reading, “Editor’s note: The Post has learned that this article contained several passages that were largely duplicated, some without attribution, from a story published by [name of news organization]. Post policy forbids the unattributed use of material from other sources.”

Among the stories flagged with the editor’s note are those about the aftermath of a massive Oregon wildfire; the death of animals in an Illinois pet store; and a wrongful-death lawsuit against American Airlines.

Post Managing Editor Cameron Barr declined to comment because it was a personnel matter.

Editors at the paper declined to say how they detected the problematic material.

Eltagouri joined the newspaper’s general assignment desk in October. She previously worked for three years as a reporter for the Chicago Tribune, most recently on the immigration and gentrification beat. She joined the Tribune in 2014 as a summer intern and eventually moved to the newspaper’s general assignment desk.

Eltagouri, a 2014 graduate of Syracuse University’s S.I. Newhouse School of Public Communications, has won a variety of journalism awards, including one for magazine writing and another for feature writing from the Society of Professional Journalists.