“It is very important that those who wear any kind of decoration earned what they wear,” said Mr. Kinard, who was deployed in an infantry division north of Seoul in 1952. “All the organizations do the best they can within the realm of the privacy act to verify that.”

One of the most extensive treatments on the subject is in the book “Stolen Valor: How the Vietnam Generation Was Robbed of Its Heroes and Its History.” A co-author of the 1998 book, B. G. Burkett, has said he helped expose the fictitious military stories of about 1,800 people.

The website Guardian of Valor, also known as Stolen Valor on Facebook, also tracks and investigates such cases, posting some of them on YouTube.

This week it included portions of a narrative that Mr. Swisher had filed in 2001 when seeking disability payments, in which he wrote that he and about 130 other Marines “came under heavy enemy gunfire” on a hill during a combat mission.

The California court’s judgment this week referred to that narrative, saying that in 2001, more than 40 years after his 1957 discharge, Mr. Swisher filed the disability claim saying he had post-traumatic stress syndrome from serving in the secret combat mission in North Korea.

His narrative as quoted in the court document described a hospital bedside visit from a captain who presented him with a Purple Heart and who said he had earned several other medals and ribbons, the court document said.

In 2004, the government began paying Mr. Swisher’s benefits for post-traumatic stress. But the next year, in an unrelated twist, he wore a Purple Heart during a trial of a man accused of soliciting a murder, apparently to use it to bolster his credibility as a witness.