Soil case study
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The document highlights key early cases in forensic geology, beginning with Georg Popp's investigation in 1904 where he used soil analysis to link murder suspect Karl Laubach to the crime scene through minerals in soil found on his person. Popp's work in 1908 further established the value of soil comparison in the Margarethe Filbert case, revealing that suspect Andreas Schlicher lied about his whereabouts based on soil found on his shoes. Additionally, Emile Gourbin's case in 1912 involved trace evidence under his fingernails leading to his confession, showcasing the evolution and importance of forensic science.
Soil case study
- 1. First criminal case using earthen materials as evidence
- 3. In October, 1904, a forensic scientist in Frankfurt, Germany named Georg Popp was asked to examine the evidence in a murder case where a seamstress named Eva Disch had been strangled in a bean field with her own scarf. A filthy handkerchief had been left at the scene and the nasal mucus on the handkerchief contained bits of coal, particles of snuff, and, most interesting, grains of minerals, particularly the mineral horneblende. A suspect by the name of Karl Laubach was known to work in a coal- burning gasworks and part-time in a local gravel pit. Popp found coal and mineral grains, particularly the mineral horneblende, under the suspect’s fingernails. It was also determined that the suspect used snuff.
- 6. Examination of soil removed from Laubach’s trousers revealed a lower layer in contact with the cloth whose minerals compared with those found in a sample collected from the place where the body of Eva Disch had been found! Encrusted on top of this lower layer a second soil type was found. Examination of the minerals in the upper layer revealed a mineralogy and size of particle, particularly a crushed mica grain, that Popp determined were comparable with soil samples collected from the path that led from the murder scene to the suspects home. From these data is was concluded that the suspect picked up the lower soil layer at the scene of the crime and that this lower, thus earlier material, was covered by splashes of mica-rich mud form the path on his return home. When confronted with the soil evidence, Karl Laubach admitted the crime and the Frankfurt newspapers of the day carried headlines such as “The Microscope as Detective.”
- 7. It is impossible to determine from the distance of almost a century how a forensic geologist or a jury today would evaluate the geologic evidence amassed by Popp. One fact is evident, mineral study had been used in an actual case, fulfilling the prophesy of Arthur Conan Doyle who had hypothesized the use of geology in criminalistics when he penned the Sherlock Homes mysteries between 1887 and 1893.
- 8. Layers of dirt leave a clear trail – the Filbert case (1908) The case that established the value of geologic information occurred in the spring of 1908. Margarethe Filbert was murdered near Rockenhausen in Bavaria. The district attorney in Kaiserslautern, a man by the name of Sohn, was seeking information on the source of some hairs found in the victim’s hands. He was familiar with Hans Gross’s text Handbook for Examining Magistrates (1893) and had filed, for future reference, clippings from the Frankfurt newspaper of 1904 describing Georg Popp’s work in the Disch case. District Attorney Sohn located Popp in Frankfort and asked him to study the hair and other material.
- 9. Georg Popp began and intensive study of the available material. He studied the hair and concluded that it came from the victim. Not easily discouraged, he extended his studies to other objects, noting with special interest encrusted soil on the dress shoes of the principal suspect, a local factory worker and farmer named Andreas Schlicher. Schlicher was a person of “low reputation who had previously been suspected of poaching.” Following the murder, many of his neighbors had suggested him as a likely suspect. It had been established that Schlicher’s wife had cleaned his dress shoes the night before the murder and that he had worn them only on that day. However, he stoutly denied having anything to do with the crime or having walked on that day in the field where the crime was committed. His trousers had been found in a nearby abandoned castle along with a rifle and ammunition used in poaching. It was established that the ammunition was his. However, he claimed that they had been left at the castle prior to the day of the murder.
- 10. Popp collected soil samples from the surrounding area. He studied these, assisted by a geologist by the name of Fischer, and observed that the area immediately surrounding the suspect’s home was littered with green goose droppings. The fields of the suspect contained a distinctive soil containing fragments of porphyry, milky quartz, and mica. Root fibers, weathered straw, and leaves were also common. Most interesting was the observation that the scene of the crime had a soil containing decomposed red sandstone, angular quartz, ferruginous clay, and little vegetation. At the castle where the trousers and gun were found, the soil contained coal, abundant brick dust, and broken pieces of cement from the crumbling walls.
- 11. Upon examining the dress shoes of the suspect, Popp was impressed with the thickly caked soil on the sole of the shoes in front of the heel. He reasoned that the soil must have accumulated as the suspect walked on the one day he had worn the shoes. That one day was the day of the murder. In addition, he reasoned that the layers of soil that accumulated on the shoes represented a sequential deposit, with the earliest material deposited directly on the leather. Careful removal of the individual layers revealed the following sequence: First a layer of goose droppings directly on the leather followed by grains of red sandstone. A mixture of coal, brick dust, and cement fragments rested on top of the sandstone. In all three layers, Popp was able to compare the material on the shoe with the soil from near the suspect’s home, the scene of the crime, and the castle.
- 12. Although Schlicher had claimed he had walked in his own fields, no fragments of porphyry with milky quartz were found on the shoes. The comparison of the soil on the shoes with the scene of the crime and the scene where the trousers were discarded indicated that the suspect had lied and had been at these places on the day of the crime.
- 13. Georg Popp made many contributions to forensic science. However, the Margarethe Filbert case established him in the field of forensic geology and set the stage for later studies of soil comparison. In this early case, he had established a time sequence of soil accumulation representing the places where a person had walked. Hans Gross had been right. The dirt on the shoes had told more than had been obtained from intensive interrogation.
- 14. Traces of red face powder beneath a suspect’s fingernails (1912) In 1912 Emile Gourbin was a bank clerk in Lyons, France. He came under suspicion of murdering, by strangulation, his girl friend, Marie Latelle. Gourbin was arrested but produced what appeared to be an air-tight alibi. Locard went to Gourbin’s cell and removed scrapings from under his fingernails. These scrapings contained tissue that might have come from Marie’s neck, but this was not provable. Locard noticed that the tissue was coated with a pink dust, which he identified as rice starch. On the particles he found bismuth, magnesium stearate, zinc oxide, and a reddish iron oxide pigment, Venetian red. Examination of the face powder used by Marie revealed that a powder prepared for her by a Lyons druggist was similar in composition. In these days of mass-produced face powder, this evidence would have far less significance. However, in 1912, because of the special preparation, it led to the confession of Gourbin.