Arthur Koehler

Arthur Koehler was an American wood technologist who lived from 1885 to 1967 and served as chief wood technologist at the U.S. Forest Products Laboratory in Madison, Wisconsin. His expertise in the identification and cellular structure of wood made him the pivotal forensic witness in the 1932 Lindbergh kidnapping investigation. Koehler traced the wood used to build the ladder found at the crime scene back through a lumber mill in McCormick, South Carolina, to a lumber yard in the Bronx, and later matched a plank missing from suspect Bruno Richard Hauptmann's attic to a rail of that same ladder by fitting the grain and tool marks together. That identification became central evidence in Hauptmann's 1935 conviction and helped establish wood analysis as a recognized forensic discipline.