The Sixteenth Rail

by Adam Schrager

  “Los Angeles,” he said in the news release announcing his departure from the lab, “has become an important center for the importation of woods from South America and the Orient. Most of these woods have never been tested and studied the way native United States species have at the Forest Products Laboratory and elsewhere. Consequently, there are lots of questions being raised about what they can be used for, what their properties are, and in fact what kind of wood they really are.”

  He would work through the war and set his retirement date for June 30, 1948. “In a way I am glad because I hope the strenuous life will be over (After we get settled in LA),” he wrote to his brothers and their families on March 14 of that year. “Of late I haven’t had quite the gumption that I used to have. It may be partly due to anticipating retirement and partly to the fact that I have had no prolonged vacation for a number of years.”

  He had spent thirty-seven years with the Forest Products Laboratory, the last twenty-five in charge of the Division of Silvicultural Relations. At sixty-three, he was ready to head west.

  His retirement would generate a three-page news release from the Forest Service, stating in part, “A little grayer—and possibly a little balder, too—than that day in February 1935, when his testimony in the Hauptmann trial catapulted him into the newspaper headlines, he is no less crisp and to the point about anything he does.”

  It was picked up in newspapers like the Chicago Tribune. Under the headline “Wood Expert Quits U.S. Post; Testified in Lindbergh Case,” the publication described him as a “key witness” in the 1935 trial of Bruno Richard Hauptmann.

  His peers were saddened at his decision to leave, pointing out that he remained in his prime.

  “As the date of your retirement approaches, I become more and more impressed with the fact that the Laboratory will sustain a great loss in your departure,” wrote George Hunt, who had taken over for Carlisle Winslow as the head of the lab in 1946. “You will gain freedom from the daily grind and the opportunity to see new country, new faces, and new tasks. We must carry on the old job without you. I think you have the better end of the bargain.” He continued his praises,

  I have consistently preached that the Forest Products Laboratory is a living organism and no one or dozen of the staff is indispensable. No matter who dies, resigns or retires, the Laboratory goes right on. This is true, but not the whole story by any means. When we lose a man like yourself, who has carried important responsibilities for a long period of years and has been our leader in an important field of work, it will take us a long time to recover from the operation. To be sure, we will go right along, but anyone watching will be able to notice a distinct limp in our gait. It will be a long time, Arthur, before we cease to miss you.

  He and Ethelyn arrived later that summer in Los Angeles. Their son, George, went with them to attend college. Arthur worked as a consultant to manufacturers, builders, and lumbermen, continuing to testify in a number of cases that required expert testimony about wood.

  But Ethelyn was unable to enjoy the retirement they’d planned for years. Within seven months of their move to California, her health began to fail with Hodgkin’s disease. She would be bedridden in the fall of 1949 and pass away in February 1950.

  “It certainly is a sad situation,” Koehler wrote to his brothers. “Here we were all ready to enjoy life together. There were many things that we planned to do, but fate decreed otherwise.”

  After retiring from the Forest Products Laboratory, Koehler taught at UCLA, Yale University, and the University of British Columbia before settling down for good in Los Angeles. He continued to enjoy spending time outside, including feeding peanuts to the scrub jays who would visit his backyard. (Courtesy: George E. Koehler)

  That summer, George would marry Margie Rennebohm, his high school sweetheart, and the three would live together in Arthur’s home. By the following spring, Koehler had proposed to Margie’s mother, Win, a widow who taught home economics at the high school level, and they would be married in the summer of 1951.

  Arthur taught night classes in wood structure and properties at the University of California at Los Angeles before taking a temporary appointment at Yale University, in its School of Forestry, from 1951 to 1953. That school issued a four-page news release on the twentieth anniversary of the Lindbergh case promoting its newest faculty member.

  “Koehler . . . is the famous wood technologist whose testimony about the kidnap ladder was so damaging to Hauptmann’s defense case,” the school news bureau wrote. “The Lindbergh trial popularized wood technology for crime detection—another in science’s long list of contributions to police work. Two bullets can be checked under a microscope to determine if both were fired from the same gun. Tiny irregularities, not visible to the naked eye, will link a type written letter with the machine used. Koehler likes to compare his wood identification methods with these exact techniques.”

  After Yale, Arthur and Win returned to Los Angeles, buying a new, smaller home on the west side of Los Angeles, near the Westwood campus of UCLA. They bought one of the earliest “pop-up” camping trailers and traveled throughout the west to places like Yosemite, Big Sur, Yellowstone, and Seattle.

  His desire to see more of the world led him to serve on the faculty at the University of British Columbia in Vancouver for one school year and where, his relatives were stunned to learn, he took dance lessons to prepare for the holiday parties held by the school.

  The couple returned to Los Angeles for good in 1957. Over the next four years, they would volunteer at their church and take fifteen separate trips, to Colorado and other places throughout the West. Sunday dinner was spent with George’s family, laughing with grandkids.

  The Hauptmann trial would never be far from his thoughts. Shortly after its conclusion, he had built a miniature to-scale replica of the ladder and put together a presentation about the wood evidence, initially using lantern slides before converting to 35mm slides. He gave speeches on his role in the case as late as 1963, thirty years after he first examined the ladder.

  “The Lindbergh case became part of his identity,” his son, George, said, “but I never heard him promote this in an unseemly way. He was basically a private man, quiet, conscientious, exacting and scientific to a fault.”

  Now in his seventies, Arthur Koehler was slowing down. He had suffered a minor stroke in 1962, and by the summer of the following year, he was confined to bed for most of the day. That winter, he had a major stroke.

  He spent his final years being cared for by Win and home nurses in attendance all day long. He still enjoyed spending time in his backyard looking at the flowers and giving peanuts to the scrub jays who’d visit.

  Arthur Koehler died at home on July 16, 1967. He was eighty-two.

  Upon his passing, every newspaper that wrote an obituary about Koehler—and there were many, including The New York Times and the Los Angeles Times—mentioned the Hauptmann trial in its opening sentence. Further, many of those articles described him as “the greatest scientist detective of modern times.”

  He could also have been called the father of forensic botany.

  As his brother Walter wrote after his death, “Now his work is done, but his influence will be felt for a long, long time.”

  Epilogue

  In 2011, the film J. Edgar, directed by Clint Eastwood and starring Leonardo DiCaprio in the title role as the legendary head of the FBI, debuted at a film festival in front of Hollywood’s elite. The biopic focused on J. Edgar Hoover’s career at America’s most famous law enforcement agency and featured a segment on the FBI’s role in the Lindbergh kidnapping and subsequent conviction of Bruno Hauptmann.

  The cast included Academy Award winner Judi Dench and other prominent actors like Armie Hammer, Naomi Watts, and Josh Lucas. Variety reported that noteworthy character actor Stephen Root joined the cast to play Arthur Koehler, “an introverted man and wood specialist who h
elps J. Edgar Hoover piece together the mystery of the Lindbergh kidnapping case through an examination of the ladder used by the abductor.”

  The film should have been the cementing of Koehler’s legacy. Except that it pronounced his name wrong, calling him Kohler, like the well-known kitchen and bath company, not Koehler (KAY-lurr). The movie character also never worked with Hoover or the FBI.

  These errors were a dramatic difference from Koehler’s status eighty years earlier, when his work riveted the nation. In fact, the Madison scientist had been mentioned in 2,653 articles in 284 newspapers in 40 states, according to the clipping service employed by the Forest Products Laboratory.

  Just after the trial he was even featured in a fifteen-minute nationwide conversation that aired before NBC Radio’s wildly popular Let’s Dance program featuring the Benny Goodman Orchestra and sponsored by the National Biscuit Company and its new product, Ritz Crackers.

  At the time, Koehler’s legacy seemed secure, but after Hauptmann was executed, dozens of books have come out about the crime, investigation, and trial, some criticizing Koehler, his methods, and his research, others labeling him a pioneer.

  Dr. Regis Miller worked in the unit that Koehler ran at the Forest Products Laboratory during the 1960s and then from 1970 to 2005. “I think Koehler did a good job,” he recently said. “Several people have looked at his work in detail. To my knowledge all of them concur that his work was based on good scientific reasoning and observation. . . . Today, we have better equipment, but I doubt we have different conclusions.”

  The elements of Koehler’s involvement in the case that are still being debated today include his matching of Rail 16 with S-226 (the attic board), his work identifying Hauptmann’s hand planer as the one that planed the ladder rungs and Rail 16, his tracing of Rails 12 and 13 using planer marks, and the testimony and evidence surrounding the ¾-inch chisel found at the kidnap scene.

  The first of those is the one that generates the most praise. There are some who believe, as Edward Reilly asserted during his closing arguments at the trial, that S-226 was planted by the police and that the original Rail 16 was discarded. However, scientists studying the board and even those who believe the investigation and trial were fraught with errors agree that the matching of the two was Koehler’s strongest work.

  “His methods cannot be criticized,” said Dr. Shirley Graham, who is a curator at the Missouri Botanical Gardens and who wrote a study on Koehler’s work. “They were the highest scientific standards of the day. . . . He employed common sense and an ability to clarify what could have been confusing to the jury in demonstrating and explaining how one piece of wood differs from another so specifically. This piece of information alone unquestionably linked the floorboard in Hauptmann’s attic to the ladder.”

  Dr. Lloyd Gardner, a professor at Rutgers University and the author of the most comprehensive and objective look at the case and trial, The Case That Never Dies, said that Koehler’s “identification of the wood in the attic looks awfully good today. I am not sure if anyone could successfully challenge it.”

  That’s what Kelvin Keraga, a senior project manager for the New York State Energy Research and Development Authority, sought to do a few years ago. He had read Scott Berg’s Pulitzer Prize–winning biography, Lindbergh, and “wanted to know more.”

  He spent three years, with the assistance of wood scientists, lumber professionals, and historians, trying to figure out if Koehler’s Rail 16 evidence was groundbreaking or inept. His report, Testimony in Wood, was featured on the television program Forensic Files.

  Keraga’s conclusion was that “trees are complex life forms, consisting of many specific characteristics. The carpentry processes used in transforming trees into boards add further individual characteristics. The intricate combination of all of these qualities in Rail 16, S-226, and the other attic boards precludes any possibility of a faked relationship, and demonstrates irrefutable evidence that Rail 16 was indeed part of Bruno Richard Hauptmann’s attic floor prior to the kidnapping.”

  Michael Melsky, who works for the US Department of Justice as a prison counselor, is one of the world’s foremost experts on the case. He is also one of the leading critics of the New Jersey State Police’s investigation and Attorney General Wilentz’s handling of the case and runs a website called the Lindbergh Kidnapping Discussion Board. He gives Koehler mixed reviews.

  “When Pope said in court there ‘was no such animal’ as a ‘Wood Expert. . .’ [i]t could be said after the trial, there now WAS such an animal,” Melsky wrote. “Koehler really worked his butt off and the skill required in order to do what he did was extraordinary. If he had just stayed within the boundaries of those investigations I believe anything he concluded would never have been challenged.”

  Koehler was an expert in wood identification, in matching wood through species and grain identification. The biggest criticism of Koehler surrounds his work in the investigation and testimony in the trial connected to tool mark identification.

  Kevin Klein is a carpenter and an avid student of the case who constructed an exact replica of the ladder found at the Hopewell estate on March 1, 1932, for the PBS program Nova. His issues with Koehler concern the scientist’s tracing of Rails 12 and 13 through planer marks.

  “I believe [Koehler] furthered the science of criminal forensic investigation,” he said. But he cautioned,

  By today’s standards, however, Koehler would be called out for his lack of training and experience in forensic tool mark identification. His testimony, if admissible, would probably have been negated by a true tool mark examiner. Not that his conclusions were unfounded, he just overstated them.

  For example, how many variables are involved in producing a given planer mark on wood? What are the odds of a match given those variables? The honest answer in court and the one a tool mark examiner will give is that the marks are consistent since there really is no way to determine whether any other cutting tool in the world would match. Basically, the difference between 1935 and now, is that an expert on tool marks would generally agree with Koehler, but not his certainty.

  The testimony surrounding the ¾-inch chisel found the night of the crime concerns both Gardner and Melsky. Koehler said in his original report that there was no way to determine what size chisel was used in the construction of the ladder, but he later testified that Hauptmann was missing a ¾-inch chisel from his tool set, intimating that they had to be one and the same.

  “What is disturbing the most,” Gardner wrote, “is the game he played at the trial when Wilentz asked him to walk by the jury box with the chisel after he had originally reported to the State Police that one could not tell what size chisel had been used.”

  In his book, Gardner said Koehler and Wilentz “had teamed up in a performance worthy of Blackstone the Magician—the most famous conjurer of the day.” He stated that the chisel hyperbole does not indicate “he was wrong about the attic board. There are credibility issues here, nevertheless.”

  Keraga said there are two possible explanations for why his view changed on the identification of the chisel: either he simply missed it in his original examination, or he created the tool mark himself. He believes there is simply no evidence to suggest Koehler was deceptive, and the change of opinion was a simple error when he first studied the ladder.

  Melsky took this a step further and said Koehler lied on the stand. The police report and Koehler’s own report show that a ¾-inch cold chisel was found in the carpenter’s chest. Melsky believes it was removed before the trial so as not to “confuse” the jury. Granted, it was not a wood chisel, but Melsky said, “Koehler was fully aware of what was found and where, so he’s obviously completely on board with what’s going on.”

  Melsky also challenged the evidence surrounding the tracking of Rails 12 and 13, stating that Koehler never found the exact match of planer marks in the samples from Dorn’s lumberyard. He foun
d the distinctive marks on the ladder rails and on a sample at the National Millwork and Lumber Company, but that sample also had another planer defect that did not show up on the ladder rails.

  Finally, Koehler has been criticized often for asking for part of the reward. As a public servant, he wasn’t supposed to put in for it, Gardner said.

  Doing so “tarnished his efforts and plays into the hands of those who believe the police framed everything and that Hauptmann was completely innocent,” said Melsky.

  Koehler did not believe Hauptmann was innocent. But he remained circumspect until his death about whether he thought anyone else was involved. Either way, he felt confident he had done his part to advance the relationship between science and crime detection.

  As he said in that February 1935 NBC Radio interview, “in all the years of my work, I have been consumed with the absolute reliability of the testimony of trees. They carry in themselves the record of their history. They show with absolute fidelity the progress of the years, storms, drought, floods, injuries and any human touch. A tree never lies. You cannot fake or make a tree.”

  Today few would dispute that assertion.

  “He opened doors for a lot of forensic experts to come, not by telling them what to do, but by demonstrating how to figure out what to do with a strong knowledge base, with an inventive but objective mindset, and with hard work and discipline,” Keraga said.

  Interestingly, even with the advent and popularity of television programs like CSI and NCIS and others featuring scientist-detectives, scientists like Dr. Graham at the Missouri Botanical Gardens worry about whether there are future Arthur Koehlers being trained. She explained, “Today, very descriptive fields in plant science such as plant anatomy, morphology and taxonomy have taken a backseat to newer disciplines based on molecular information and increasingly on more sophisticated computer-based statistical programs of assessing data.” Graham continued,