‘CSI’ in 1920? ‘American Sherlock’ tracks a pioneer in forensics

Kate Winkler Dawson follows the career of Edward Oscar Heinrich, who nudged criminal investigations beyond hunches toward a more scientific approach. 

In 1923, in a plan that went tragically awry, the DeAutremont brothers – twins Ray and Roy, and younger brother Hugh – attempted a robbery of a Southern Pacific Railroad train. During the botched operation, the mail coach carrying the cash they’d intended to steal burned. They killed four crew members before running from the scene empty-handed.

Though inept as robbers, the brothers had done a decent job of covering their tracks. Investigators, however, recovered a bag with a pair of overalls, stained with pine tar, near the scene. Days later, while an innocent mechanic languished in a jail cell, police brought the overalls to Edward Oscar Heinrich, one of America’s first forensic scientists and the subject of Kate Winkler Dawson’s lively and captivating biography, “American Sherlock: Murder, Forensics, and the Birth of American CSI.” 

Heinrich spent hours scrutinizing the overalls: measuring, photographing, and jotting down notes, painstakingly examining hair and debris under a microscope. Thanks to his meticulous records, archived at the University of California, Berkeley, Dawson was able to reconstruct the precise steps that led Heinrich, in a remarkable feat of forensic science for its time, to confidently inform investigators that the overalls belonged to a slightly built white lumberjack who’d worked with fir or spruce trees, soon identified as Ray DeAutremont. Heinrich’s work on the case culminated, after a long manhunt, with the suspects’ apprehension. 

“American Sherlock” delves deeply into Heinrich’s methods as he investigates various crimes; these sections are the fascinating meat of the book. (Readers should be aware that several of the forensics photographs included in the book are gruesome.) Dawson is less successful in her depiction of the criminalist as an insecure and somewhat fusty perfectionist, forever fretting over his finances. In the early 20th century, she explains, “criminal investigations were predominately ‘solved’ on hunches – the instincts of experienced but ill-equipped detectives who sniffed out suspects based on motive, a dangerous guessing game that leaned on mistaken intuition.” Such was the process that landed the unfortunate mechanic in jail after the attempted train heist.

Heinrich introduced a number of groundbreaking methods that are still in use and changed the way crimes are solved. According to Dawson – whose first book, “Death in the Air,” centered on the serial killer who struck during London’s Great Smog of 1952 – Heinrich was the first investigator in America to document the use of forensic entomology (establishing a person’s time of death through insect life cycle development in their body). He also advanced the field of forensic geology, linking perpetrators to victims through microscopic analysis of grains of sand found on each. In addition, he invented the method of using a comparative microscope to produce side-by-side images of bullets; because firearms leave tiny grooves on spent bullets, displaying an enlarged image of a bullet recovered from a crime scene together with an image of a test bullet fired from a weapon can definitively link the weapon with the crime. Dawson calls this work “revolutionary.”

The author refers to her subject as “the most famous criminalist you’ve likely never heard of,” but Heinrich was well known during his lifetime, testifying in high-profile criminal cases throughout his 40-year career. In fact, the link to the beloved Arthur Conan Doyle character came from the media, which dubbed him the “American Sherlock Holmes.” A rare case that didn’t go his way was perhaps also the most scandalous one in which he was involved. Silent film actor Roscoe “Fatty” Arbuckle was charged with rape and manslaughter after the 1921 death of actress Virginia Rappe and acquitted after two mistrials. Heinrich, who regarded Hollywood with snobbish disdain, was convinced of the star’s guilt, but his expert testimony, which relied on fingerprint analysis, failed to convince three juries. 

The evidence Heinrich presented in that particular case would these days be considered unreliable, as were some other types of evidence he championed. As Dawson notes in assessing his legacy, Heinrich “advanced some dubious methods, including handwriting analysis and bloodstain pattern analysis – both now considered junk science.” Still, Dawson establishes that Heinrich was a true pioneer in his field. Long before the advent of DNA profiling, toxicology tests, and other technologies that forensic scientists rely on today, the American Sherlock had helped solve some 2,000 cases – and he made it all look elementary.