New York ? A New York Times reporter “committed frequent acts of journalistic fraud,” including stealing material from other newspapers, inventing quotes and lying about his whereabouts, according to an investigation conducted by the paper.

The review found problems in at least 36 of the 73 articles written by Jayson Blair from the time he began receiving national reporting assignments in late October to his May 1 resignation. The Times described the episode as “a low point in the 152-year history of the newspaper.”

Blair, 27, “used these techniques to write falsely about emotionally charged moments in recent history, from the deadly sniper attacks in suburban Washington to the anguish of families grieving for loved ones killed in Iraq,” according to a story the Times posted on its Web site Saturday before its publication in today’s editions.

The 7,500-word story was accompanied by an editor’s note apologizing to Times’ readers and a detailed accounting of articles in which falsification, plagiarism or other problems were discovered by a team of Times reporters and researchers.

“It’s a huge black eye,” Arthur Sulzberger Jr., chairman of The New York Times Co. and publisher of the newspaper, said in the article. “It’s an abrogation of the trust between the newspaper and its readers.”

The inquiry into Blair’s work continues, especially on more than 600 articles he wrote before his sniper coverage began in October. The newspaper asked readers to report problems by e-mailing a special address: retrace@nytimes.com.

The Times cited several reasons for not detecting the problems with Blair, including “a failure of communication among senior editors; few complaints from the subjects of (Blair’s) articles; his savviness and his ingenious ways of covering his tracks.”

Blair attended the University of Maryland, but did not graduate, and joined the Times in 1999 after an internship the previous year. He did not return a call from The Associated Press, and the Times said he rejected repeated requests to help the newspaper in its inquiry or comment on his work.

In a letter sent to the Times and read to the AP after his resignation, Blair blamed “personal issues” and apologized for his “lapse of journalistic integrity.”

The review began after the editor at the San Antonio Express-News pointed to similarities in an April 26 piece by Blair and a story that appeared earlier in the Texas paper.

The story concerned a woman’s monthlong wait for news on her son, a soldier missing in Iraq. The Times said at the time it was unable to determine whether Blair had done any original reporting for the piece, and Blair quit within days.

The investigation showed that while he was filing stories with datelines from around the country, Blair was often in the New York City borough of Brooklyn, even filing expense receipts from stores and restaurants there.

In other instances:

• On Oct. 30, Blair wrote that John Muhammad, one of the two sniper suspects, had been talking with local investigators for more than an hour when federal authorities forced an end to the interrogation — perhaps as Muhammad was ready to confess. But law enforcement officials told the Times that the conversation with Muhammad was focused on minor matters, such as arranging for a shower, rather than “explaining the roots of his anger” as Blair reported.
• On March 27, Blair wrote under a dateline from Palestine, W.Va., about the family of Pvt. Jessica Lynch, a POW rescued in Iraq. He described how Lynch’s father “choked up as he stood on his porch here overlooking the tobacco fields and cattle pastures.” The porch overlooks no such thing, the Times said, and no member of Lynch’s family remembers talking to Blair.