Politico reporter Kendra Marr has resigned after an editorial investigation determined she had borrowed from the work of others, without attribution, in ways which [Politico editors] cannot defend and will not tolerate according to an Editor's Note published on the Politico Web site.

Marr's violations were discovered after New York Times reporter Susan Stellin emailed Politico about an Oct. 10 story written by Marr that bore close resemblance to a story Stellin wrote two weeks earlier, according to Poynter.org. After an investigation of Marr's work, editors determined that Stellin's claim was legitimate, and found six further examples of improper use of sourcing.

The blog Regret the Error pointed out that the Editor's note, signed by John F. Harris and Jim VandeHei, did not use the word plagiarism at any point.

The letter states that some of Marr's stories bore troubling similarities to work earlier published by others but added that there was no evidence of invention of quotes, scenes, or other material.

The post included links to seven corrected stories that the editors deemed in violation of journalistic standards.

The letter also claims that Marr offered her resignation (rather than having been fired, as some outlets are reporting) and described her as a friend and colleague who has produced much outstanding work here and elsewhere.

Politico has since removed Marr's bio from its Web site, and her name is no longer listed in the drop-down search list of reporters' names.

Marr's Twitter and Facebook pages both continue to list Politico as her employer. According to her Twitter profile, she is also an aspiring baker. There is no word on whether she uses original recipes in her confections.

Marr is a graduate of Northwestern University and previously worked at The Washington Post.

This is not the first time Marr has been in journalistic hot water.

As a Northwestern student, she falsely claimed to be a U.S. Census worker in order to get information for a class assignment, according to a Poynter.org report that cites The Chicago Tribune. Marr's professor David Protess was put on leave as a result of that incident and one where another student pretended to be a ConEd worker.

Protess has defended his students' actions, but Marr expressed regret.

I was a student in the class, and I wish I hadn't done it, Marr told The Chicago Tribune in May. It wasn't my idea, and as a professional journalist, I haven't misrepresented myself since, nor do I intend to ever again.

On Friday, The Washington Post published a story on the resignation, and acknowledged in the article that Marr previously worked at the publication. Prior to Friday's article, a Washington Post blogger published multiple stories on the incident, and included a disclaimer on one that Marr had previously worked at the Post.  The Post also published an AP story on  the plagiarism charges earlier this week. Links to Marr's previous articles are still active, and on Sept. 26 the Post cited and linked to Marr's Sept. 26 story that was later found to have improperly drawn on reporting from Scripps Howard.

In Friday's story, Washington Post reporter Paul Farhi cited a Politico colleague speaking on condition of anonymity who said that Marr was new to her transportation policy beat and felt 'extreme pressure' to get up to speed.