The man cutting a path across the Marine Corps birthday ball near Atlantic City last fall wore row upon row of battle ribbons on his chest, silent testament to a history of gallantry and sacrifice. Among 10 awards were a Bronze Star, the Silver Star and the Navy Cross, second in significance only to the Medal of Honor.

Retired Marine Corps Master Sgt. Fred Montney III and others admired Gerard Smigel, 52, in his dress blue uniform and wearing the rank of lieutenant colonel. "He was in his element. He enjoyed it," Montney said.

As the night wore on, Montney noticed little flaws. Smigel would excuse himself to go to the "latrine." Marines call it the "head." Smigel wore one award, a Combat Action Ribbon, upside down. "When I asked him questions, he would get somewhat fuzzy" about details, Montney recalls. The retired master sergeant snapped a photo of Smigel, smiling next to his wife and later called the FBI.

Smigel pleaded guilty this month in federal court to illegally wearing the uniform and medals. He was sentenced to three years of probation and fined $3,000.

Masquerading as a war hero has become riskier — and more tempting — during this time of war. "Right now, most everybody loves the military, and that's why I'm seeing more and more of these impostors," says senior FBI agent Thomas Cottone Jr. In the past five years, the FBI has investigated 58 people for phony heroism. Of that number, 20 cases are pending. Of the other 38, almost 60 percent ended in convictions.

Support in Congress is growing for the "Stolen Valor Act," which would stiffen penalties for falsely claiming to have received any medal. Assisted by military researchers and the Internet — where hoaxes are quickly tracked and broken — the FBI could end up investigating more cases of medal fraud this year than ever, Cottone says. He says he gets one tip a week.

"I call them gutless creeps," Montney says of frauds such as Smigel. Court documents show Smigel's true military service was as an Air Force plumbing specialist who received a less-than-honorable discharge in 1975.

'LOW SELF-ESTEEM'

"The vast majority, it's just low self-esteem," says B.G. "Jug" Burkett, a retired stockbroker from Dallas who led efforts to unmask frauds with his 1998 book, "Stolen Valor." Burkett says people assume heroic alter egos to offset shortcomings.

"Whenever you make someone a hero, he's not only heroic, he's trustworthy, he's honest, he's loyal, he's sincere. All these other attributes get attached to him," Burkett says. "And if somehow he has failed in some way, then it's due to that evil war that he was forced to fight. You can take both the good and the bad, and it explains everything."

The FBI is currently investigating two alleged impostors: Theodore Bantis, 59, of Dunlap, Ill., and Richard Thibodeau, 64, of Lawrenceville, Ga. Both have asserted for years that they were decorated Marine Corps officers and Navy Cross recipients, Cottone says.

Media reports show Bantis claimed to have received eight Purple Hearts in combat, something military researchers say has happened to only five men in U.S. history. Thibodeau explained himself in a May interview with the Atlanta Journal-Constitution. "In my mind, I wasn't harming anyone because I wasn't capitalizing on it," he said, although he has since pleaded guilty.

HEFTIER PUNISHMENT

In past decades, laws against impersonating war heroes were sporadically enforced, Cottone says. That changed in the 1990s, largely because of Mitchell Paige, who received the Medal of Honor in 1942 for beating back a Japanese assault on Guadalcanal. Paige died in 2003. During his retirement, Paige tracked people who falsely claimed to be Medal of Honor recipients. In 1994, he successfully lobbied Congress to pass a law that made selling or falsely wearing the Medal of Honor punishable by up to one year in jail and a $100,000 fine.

Cottone, who worked with Paige, used that law to investigate H.L.I. Lordship Industries, a company in Long Island, N.Y., that held a contract with the Pentagon to produce Medals of Honor. In 1996, Cottone proved the company had illegally sold 300 awards, many of them snapped up by impostors. The firm lost its government contract and paid a $22,500 fine.