McKay Smith is used to keeping secrets. A lawyer with the Justice Department's National Security Division, he advises U.S. intelligence agencies on the legality of some of the country's most highly classified operations. The division oversees electronic surveillance and counterterrorism, and on a daily basis Smith might find himself eyeballs deep in classified memoranda and documents that will probably never see the light of day in his lifetime. The discovery of a 70-year-old military intelligence report written by a young Army Air Corps lieutenant, however, stopped Smith cold and led him to take on a new, public role.

Three years ago, Smith obtained a copy of a once-secret "escape and evasion report," in which one Lt. Raymond Murphy describes in precise detail how he bailed out of his flaming B-17 bomber over Avord, France, on April 28, 1944, and survived for the next four months behind enemy lines before making his way to England. Murphy had been part of a mission to attack a German-held airfield less than six weeks ahead of the D-Day landing at Normandy, which marks its 70th anniversary this Friday. Amid the harrowing stories of the airman's hard parachute landing, his efforts to avoid capture by German soldiers, and his exploits with French Resistance fighters, Smith spotted two barely legible lines, handwritten in pencil, at the end of the neatly typed document: "About 3 weeks ago, I saw a town within 4 hours bicycle ride up the Gerbeau farm where some 500 men, women, and children had been murdered by the Germans. I saw one baby who had been crucified."

Smith, a self-made World War II historian with an outsized passion for document research, concluded that based on Murphy's description of the scene and his location at the time, the young airman had seen the aftermath of a notorious massacre at Oradour-sur-Glane, a town in west-central France. On June 10, 1944, four days after the Allied landing at Normandy, a unit of the Waffen-SS, the Nazi Party military wing, descended on the village and killed 642 men, women, and children. It was one of the largest mass murders of French civilians during the German occupation, and an act of retribution against the townspeople for their perceived assistance to the French Resistance and the invading American forces.

The story of Oradour is well known to historians of the war, though less so to many Americans, who are more likely to recall the bloody U.S. landings at Omaha Beach and other sites along the French coast on D-Day. But those two handwritten sentences at the end of Murphy's report might be unique in American history. As far as Smith knows, there is no other account by a U.S. military service member of the massacre at Oradour. Murphy stands as a lone witness among the American men who fought -- and in many cases died -- to liberate France in 1944.

Seventy years later, that testimony could help deliver some long-denied justice for the victims of the French town. In January of this year, former SS soldier Werner Christukat, who was 19 when his unit razed Oradour, was indicted in Germany for allegedly assisting in the murder of 25 people, either by "taking on blockading duties" while the Germans rounded up the townspeople, or carrying "flammable material into the church," where the women and children were locked inside and then burned alive, investigators say. The men, according to eyewitness accounts from survivors, were lined up, shot in the legs with machine guns so they'd die slowly, and then set ablaze. Christukat denies that he was directly involved in the crimes.

"There's no doubt that this is a significant war crime, and on a scale that it has to be known about," Smith said in a recent interview, noting that he was speaking in his personal capacity and not on behalf of the Justice Department. If Murphy's account was accurate, he has provided new evidence of the slaughter -- evidence that remained undiscovered for seven decades until Smith found it on a U.S. government website.

Today, Oradour is but ruins -- brick houses where homes once stood, a rusting car. It's a "ghost village," preserved by presidential decree as a testament to German atrocities. German soldiers sacked several French villages, but none so viciously as Oradour. In January 2013, German investigators opened a new inquiry into the killings, prompted by documents uncovered in the archives of the Stasi -- the former East German secret police force -- about six German soldiers who were believed to have taken part in the massacre and were still alive. The East German government had refused to extradite them to a tribunal in Bordeaux in 1954, and they have never faced justice for their alleged crimes. Twenty soldiers were convicted for crimes at Oradour, but all of them were eventually set free. To date, only one former German soldier has spent significant time in prison for the killings (an officer who was convicted in 1983), but he was released 14 years later and lived another decade as a free man.

Smith is closely following the Christukat case. He said that while it may be unlikely that Murphy's account will end up being presented in court, given its significance and the D-Day anniversary, it could become "a lightning rod for public consciousness," so that even 70 years later, no one forgets what happened at Oradour, and so they know at least one American spoke up.

And now two. Smith has had years of practice combing through archives and pursuing information that some people might prefer not be found. But he was more highly motivated than usual to find the escape and evasion report. Lt. Murphy was Smith's grandfather, a man he never met, and who Smith's own father never knew. Not long after the war, Murphy's wife left her husband, taking their newborn son with her, and she never saw him again. Murphy died in 1970.

"He had a problem with the ladies," Smith said his grandmother used to say. He never pried. But three years ago, he began a quest to fill out the story of Raymond Murphy, a man who loomed over his life mostly in legend. The documents brought him closer to his grandfather than he'd ever been, and closer to the savagery of the war than he'd ever expected.

Mostly using the Freedom of Information Act -- a tool that journalists employ to pry loose secret documents from government hands -- Smith has sent out records requests for everything he could think to ask about his grandfather. In addition to the escape and evasion report, he obtained a host of other documents about the men who flew with Murphy, as well as photographs from the fateful bombing raid over Avord. One shows the moment just before Murphy's B-17 took anti-aircraft fire, forcing all 10 crew members to bail out moments before the aircraft exploded in midair.

Smith has had to become a student of some of the darkest moments of the Second World War. At least one scholar whom he has contacted raised the possibility that Murphy actually saw the aftermath of a German attack on the city of Saint-Amand-Montrond, near where Murphy was working with Resistance fighters. But Smith doubts this was the scene his grandfather described. Murphy knew Saint-Amand-Montrond and mentions it by name elsewhere in his account. But when he recalls the dead civilians, he writes only of "a town." It must have been somewhere he'd never visited or didn't know well, Smith concluded. Oradour is also about the distance, by bicycle, from the farm of a local resistance leader, Camille Gerbeau, where Murphy was hiding out.

But there's grimmer evidence that Murphy was at Oradour -- far fewer people died in the other villages, Smith said. Murphy reports seeing 500 dead men, women, and children, and while it's possible he overestimated the number, that scale of killing most closely matches the massacre at Oradour, Smith said. And nowhere in the historical record is there evidence of such shocking cruelty to a baby. Murphy's report is matter-of-fact and precise, down to the number of rations and the amount of money he had on him when he dropped into a French field. There's no reason to believe he made up a story about a crucified child, Smith said.

The documents bring far-off history into sharp, intimate relief. But they have their limits, particularly when it comes to obtaining some justice for the victims of Oradour. Smith has re-examined his grandfather's interview through the eyes of an attorney trained in investigations. (Before coming to the Justice Department, he was a senior inspector and an intelligence officer in the Department of Homeland Security's Office of Inspector General, where he said he oversaw hundreds of interviews.) Smith said there are few indications that the military intelligence officers who interviewed his grandfather and managed his debriefing realized just how serious his allegations were. The note about the dead villagers and the baby is transcribed into the margins of an initial draft of the report, and it wasn't included in the final version. Also, the officer conducting the interview with Murphy recorded no further information about the grisly scene.

But that's not surprising, given the nature and purpose of an escape and evasion report. It's a tactical document meant to record how airmen had survived shootdowns and the dangers of life behind the lines, and then to pass that knowledge on to others, Smith said. The report was never intended to capture evidence of war crimes.

Murphy's escape and evasion report wasn't declassified until 1974, three decades after the D-Day landing, which suggests the military saw the document first and foremost as a piece of intelligence that needed to be kept secret to safeguard combat techniques. The report was only put online in September 2010, on the website of the National Archives and Records Administration, which is where Smith found it about six months later.

One is left to wonder whether Murphy intended to tell his Army interviewers about the carnage he saw in Oradour, or if the note was an afterthought. Murphy never spoke of the massacre to his family, Smith said. He surmises that his grandfather, a deeply religious Catholic, was so distraught by the image of a crucified child that he chose never to mention it again. Smith also points out that his grandfather signed a secrecy oath in 1944, promising never to talk about the shootdown and the circumstances of his escape. It seems he honored the pledge for the rest of his life.

The earlier draft with Murphy's note was affixed to the final report, but it was almost certainly overlooked by the officer who approved the report and others higher in the chain of command, Smith said. There's no indication that the report was ever used as evidence in Nazi war crimes tribunals, which in any event had mostly concluded a quarter century before the document was declassified. But with the new investigations and a pending trial against Christukat, Murphy's account could be re-examined. Even if those few faint lines aren't read out in a German courtroom, Smith feels affirmed knowing that one alleged killer might, at last, be held to account.

"To me, that's very strong evidence of the immutability of justice," he said.

Photo: Courtesy McKay Smith

Photo illustration: Ed Johnson for FP