Updated — January 2005

This page summarizes recent publications that involve forensic geological evidence, analytical methods and tools. These are provided as examples of the role of forensic geology in a variety of cases. The summaries are prepared by Dr. Reid.

Selected judicial cases are forthcoming where geological evidence was involved. Some historical cases are planned to be included.

Contents

Recent papers

• Geographic information systems (GIS) liabilities
• Geologist Analyses Soil Samples to Assist the Search for a Missing Person

Judicial cases

• Forthcoming

Recent papers

• Geographic information systems (GIS) liabilities

Duncan (2004) examines the nature of professional negligence and malpractice, and the liability exposure of individual geologists and geographic information system (GIS) professionals related to their production of digital spatial data.

Duncan points out that "...much geologic data was collected for a limited purpose and do not have the accuracy or completeness that many end users would prefer or need." The example that he provides is "...end-users conducting field work based on high accuracy GPS [global positioning system] devices may be using geologic data collected on a topographic base map with far less accuracy. To address such problems, efforts should be made towards adequate characterization of the accuracy, the resolution, and completeness of the datasets. By characterizing the quality of the data in such a way that the end user can understand its limitations, a geologist or GIS professional can reduce personal liability and increase the utility of the data. Unfortunately most data producers have chosen to rely on disclaimers rather than attempting to used metadata [data about data] to limit liability."

Onsrud (1999), cited in Duncan (2004), has suggested that judges recognize that mistakes and blunders are inevitable. Error-free data, ideal for all applications, is not the court's expectation. Rather, courts are likely to ask questions in the form:

• Are the data collected and assembled in a consistent manner, reflecting best practices of the profession?
• Is a good faith effort made to characterize the data quality in terms of accuracy and completeness?
• Are data quality information presented in such a way that a reasonable person could be expected to gauge the appropriateness of the data for a particular purpose?
• Are nationally accepted data formats for metadata standards followed?
• Are the standards implemented in a reasonable and competent manner?

  References cited:

  Duncan, Ian J., 2004, Negligence and professional malpractice related to GIS datasets, U.S. Geological Survey Open-file report 03-471, Digital Mapping Techniques '03 — Workshop Proceedings, June 1-4, Millersville, Pennsylvania. David R. Soller, Editor, pages 41-45.

  Onsrud, H.J., 1999, Liability in the use of GIS and Geographical Data Sets, in Longley, P., Goodchild, M.F., and Maguire, D. eds., Geographical Information Systems, v. 2, London, Longman, pages 643-652 (not seen).

• Geologist Analyses Soil Samples to Assist the Search for a Missing Person

A USGS geologist based in St. Petersburg, Florida, was requested to assist the Sheriff of Lee County, Florida, to narrow the range of locations to search for a missing person. A young woman was reported missing from Ft. Meyers, Florida, in early January. She was last seen with a male companion that she had met on the Internet a year earlier and had invited down from Washington State to stay with her. The male friend, now "suspect' was picked up in Corpus Christi, Texas, on a separate charge. He was driving her car, which contained most of her belongings. The victim was not with him and as of June 2004 (press release time) she was still missing.

The Texas authorities found soil samples in the trunk of the car and on the floor of the rear passenger side. In addition, a shovel was found in the trunk with a few grains of sand on it. The suspect used the victim's credit card on the trip from Fort Meyers to Corpus Christi, leaving a trail from south Florida to Goodyear (near Phoenix) Arizona, and back to Corpus Christi. The suspect's route had followed Interstate Highway 75 northward through Florida, jointed Interstate Highway 10 (I-10) in northern Florida, and followed it all the way to Goodyear, Arizona.

The two soil samples found in the car consisted of calcium carbonate-cemented sand grains — rather typical Florida sediment. The few grains recovered from the shovel, however, are igneous, consisting of quartz, plagioclase, and a black mineral that looks like hornblende. This mineral assemblage is not typical of Florida or the southern Gulf Coast, including the part of Texas traversed by I-10. Granitic rocks of Precambrian age occur in the Llano Uplift, north of San Antonio, but those rocks contain abundant orthoclase, none of which was apparent in the shovel sample.

The USGS geologist contacted Arizona Department of Mines and Mineral Resources that confirmed that that State had a lot of material similar to the sediment on the shovel. With this information, the Lee County Sherriff's investigators redirected their search for the victim form Florida to Arizona. As of 30 June 2004 (press release time) the victim had not been found.

Reference cited:

Geologist Analyzes Soil Samples to Assist the Search for a Missing Person, viewed at http://soundwaves.usgs.gov/2004/06/research3.html on 30 December 2004. The page is time stamped as of 30 June 2004 @1347 hours.

Judicial cases

• Forthcoming

Dr. Jeffrey C. Reid, P.G., CPG, President, ForensicGeology, Inc. He is also an Adjunct Associate Professor, Dept. of Marine, Earth and Atmospheric Sciences, N.C. State University, Raleigh, NC, where he teaches forensic geology. Dr. Reid is an AIPG Certified Professional Geologist (CPG) and is a licensed geologist in North Carolina, South Carolina, Tennessee and Texas.

For additional information:

Contact Dr. Jeffrey C. Reid, President, ForensicGeology, Inc., by e-mail at jreid@forensicgeology.com, or by telephone 919.618.0810. Our mailing address is below.