Welcome to Tread Forensics

/Tread Forensics is a website dedicated to providing footwear and tire resources to the forensic community. The site went live in April 2017 and was created to perpetuate the online resources available at SWGTREAD.org.

The Scientific Working Group for Shoeprint and Tire Tread Evidence (SWGTREAD) was created in 2004 by the FBI Laboratory to standardize and advance the forensic analysis of footwear and tire impression evidence. The first meeting took place in September 2004 and the last in March 2013. From 2004 to 2013, the working group was co-funded by the FBI and the National Institute of Justice (NIJ). However, In October 2014, the Footwear and Tire Subcommittee of the National Institute for Standards and Technology (NIST) Organization of Scientific Area Committees (OSAC) was created. At that point, SWGTREAD decided to discontinue its operations and focus its efforts on supporting the subcommittee; however, the OSAC subcommittee identified the latest versions of the SWGTREAD standards as the baseline documents that best reflect the current state of the practice of forensic footwear and tire analysis and thus re-published them on the subcommittee's website.

During the 20th century, scientists in most forensic sub-disciplines reported categorical opinions on the source of material recovered in connection with a crime. Following the development of DNA evidence, legal and scientific scholars have urged these scientists to determine the probative value of forensic evidence in a more transparent way and to present conclusions in a fair and balanced fashion. Unfortunately, statistical information is not well understood or used rationally by most individuals when reasoning. Most jury studies have focused on jurors' understanding of reporting techniques currently used by the profession; very few studies have attempted to develop novel reporting techniques based on cognitive-psychological findings on efficient communication. This study explores some possible reporting techniques and describes some of the main challenges of the development and testing of novel conclusion presentation methods. Some of our main findings are similar to other jury studies. Study participants did not entirely account for the forensic evidence when updating their belief that the considered source was in fact the true source of the trace, however, participants provided with likelihood ratios showed less variability in their answers compared to participants provided with categorical conclusions. In addition, we observed a systemic bias against the defendant prior to hearing the forensic evidence. Finally, we found that recording participants' beliefs involved solving a circular conundrum: measuring the variability in the participants’ understanding of quantitative information requires the use of quantitative scales that they may not all perceive in the same way.

Upcoming Events

Technical Colloquium on the Weight of Evidence
June 27-29, 2017
NIST, Gaithersburg, MD


2017 International Forensic Science Error Management Symposium
July 24–28, 2017
NIST, Gaithersburg, MD
Registration opened March 31


IAI Educational Conference
August 7–11, 2017
Atlanta, Georgia
Registration open


10th International Conference on Forensic Inference and Statistics
September 5–8, 2017
University of St. Thomas, Minneapolis, MN
Registration open