WASHINGTON — For more than a year, former Marine Staff Sgt. Jimmy Massey has been telling anybody who would listen about the atrocities that he and other Marines committed in Iraq.

In scores of newspaper, magazine and broadcast stories, at a Canadian immigration hearing and in numerous speeches across the country, Massey told how he and other Marines recklessly, sometimes intentionally killed dozens of innocent Iraqi civilians.

Among his claims:

• Marines fired on and killed peaceful Iraqi protesters.

• Americans shot a 4-year-old Iraqi girl in the head.

• Tractor-trailers were filled with the bodies of civilian men, women and children killed by American artillery.

Massey's claims have gained him celebrity. Last month, Massey's book, "Kill, Kill, Kill," was released in France. His allegations have been reported in nationwide publications such as Vanity Fair and USA Today, as well as numerous broadcast reports.

This year, he joined the anti-war bus tour of Cindy Sheehan and he's spoken at Cornell and Syracuse universities, among others.

News organizations worldwide published or broadcast Massey's claims without any corroboration and in most cases without investigation. Outside of the Marines, almost no one has seriously questioned whether Massey, a 12-year veteran who was honorably discharged, was telling the truth.

He wasn't.

Each of his claims is either demonstrably false or exaggerated — according to his fellow Marines, Massey's own admissions and the five journalists who were embedded with Massey's unit, including a reporter and photographer from the St. Louis Post-Dispatch and reporters from the Associated Press and the Wall Street Journal.

Massey, 34, of Waynesville, N.C., was with the 3rd Battalion, 7th Marines based out of Twentynine Palms, Calif. The unit went to the Middle East in January 2003 and participated in the U.S. invasion of Iraq.

Massey was discharged in December 2003, shortly after returning from Iraq, due to depression and post-traumatic stress syndrome.

He began turning up in news stories last spring with accounts of military atrocities. Massey's primary claim has been that Marines from his battalion — some of whom, he told a Minneapolis audience, were "psychopathic killers" — recklessly shot and killed Iraqi civilians, sometimes, he said, upon orders from their commanders. During a hearing in Canada, Massey said, "we deliberately gunned down people who were civilians."

The Marine Corps investigated Massey's claims and said they were "unsubstantiated."

From the beginning, Massey misled reporters.

In early interviews, he told how he had lost his job at a furniture store because of his anti-war activities. But when asked about the incident in an Oct. 19 interview with the Post-Dispatch, Massey said that he had quit his job but never felt pressure to leave.

"I left on good terms," he said.

He also backtracked from allegations he made in a May 2004 radio interview and elsewhere that he had seen tractor-trailers filled with the bodies of Iraqi civilians when Marines entered an Iraqi military prison outside of Baghdad. He said the Iraqis had been killed by American artillery.

He told listeners the scene was so bad "that the plasma from the body and skin was decomposing and literally oozing out of the crevices of the tractor-trailer bed."

He repeated the story during the Post-Dispatch interview. But when told that the newspaper's photographs and eyewitness reports identified the trailer containing all men, mostly in uniform, Massey admitted that he had never seen the bodies.

Instead, he said, he had received his information from "intelligence reports." When asked if those reports were official documents, he answered, "No, that's what the other Marines told me."

The details of Massey's stories changed repeatedly.

For example, he almost always told his audiences and interviewers of an event he said he'd never forget: Marines in his unit shooting four Iraqi civilians in a red Kia automobile.

In some accounts, Massey said Marines fired at the vehicle after it failed to stop at a checkpoint. In another version, he said the Marines stormed the car.

Sometimes he said three of the men were killed immediately while the fourth was wounded and covered in blood; sometimes he said the fourth man was "miraculously unscathed."

Sometimes he said the Marines left the three men on the side of the road to die without medical treatment while the fourth man exclaimed: "Why did you shoot my brother?" In other versions, he said the man made the statement as medical personnel were attempting to treat the three other men, or as the survivor sat near the car, or to Massey personally.

There is no evidence that any of the versions occurred.

Massey told a version of the story before an immigration hearing in December in support of an American soldier trying to flee to Canada. The Seattle Times reported Massey's allegations in a story about that hearing. Then, Massey said he and the Marines killed four of the demonstrators. In other interviews, he said the Marines shot at 10 demonstrators and killed all but one that he let crawl away.

In interviews with more than a dozen 7th Marines and journalists who were in the military complex that morning, none can recall such an incident.

The Marine Corps readily admits that some of its men shot civilians, but not intentionally, they said. The Post-Dispatch reported on the second day of the war that Marines in one battalion had mistakenly shot and killed members of a British-based television network while shooting at Iraqi attackers.

When Marines moved into Baghdad a month later, the Post-Dispatch reported two separate automobile-related incidents in which Marines from Massey's battalion inadvertently shot and wounded 12 civilians. All of the passengers survived following treatment by medical personnel.

One of the checkpoint shootings is apparently the basis for one of most shocking recollections claimed by Massey in numerous speeches and interviews: The shooting of a 4-year-old girl in the head.

While touring with Sheehan in Montgomery, Ala., he told of seeing the girl's body. "You can't take it back," he said, according to the local newspaper.

But in the interview with the Post-Dispatch, Massey admitted that he had never seen the girl.

No 4-year-old died in the incident or was even wounded, according to witnesses, including a Post-Dispatch photographer at the scene who filed photos of the incident that were published in the newspaper.