Slip and Fall Expert Witness

John C. Sotter
Vice President

Consultant and Expert Witness — Slip, Trip and Fall

26705 Loma Verde
Mission Viejo, CA 92691-6055

TELEPHONE/FAX: 949-933-6971


John Sotter - Senior Technician

Curriculum Vitae

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Vice President John Sotter graduated from the University of California at San Diego in 1992 with a Bachelor of Arts in Urban Planning. His studies there included work in floor friction and in chemistry.

He has 17 years of experience in responsible safety work for the City of San Clemente, California.

He has trained in floor slip resistance testing in the U.S. and the U.K. (including pendulum and Tortus manufacturing facilities) and has done most of Sotter Engineering’s floor slip resistance testing work for the past twenty years, doing testing for more than 1,000 individual clients, both in our laboratory and in the field from Hawaii to Maine, British Columbia to Mexico, New York to Florida, and everywhere in between. He has tested floors and road surfaces for some of the world’s largest international corporations.

John’s twenty years of extensive experience with floor slip resistance testing using the BOT-3000E, British Pendulum Tester, Tortus digital tribometer, SlipAlert, and ASTM C1028 static friction test device, is unmatched both in the United States and in the Americas. He has worked in floor friction testing and floor friction treatment in the USA, Canada, Mexico, and on the high seas. He helped develop an anti-slip floor coating that has now been sold in dozens of countries.

John has testified in court once, and has been deposed once. He has worked with dozens and dozens of lawyers on slip and fall lawsuits, almost all of which were settled before deposition or trial was required. This is probably in large part due to the fact that John uses internationally-accepted and peer-reviewed science, and he is very knowledgeable about the withdrawn, expired and unreliable test methods used by most American slip and fall experts. He works behind the scenes with lawyers to get the testimony from unscrupulous experts with their unreliable instruments and data thrown out of court. Settling a lawsuit when one expert is presenting internationally-accepted testing data, and the other is using an old, withdrawn American standard with poor precision can be quick and easy.

John’s background includes many miles barefoot on wet surfaces: years of competitive swimming, international sailing, water polo (a high school All-American), and surf lifeguarding. John has traveled extensively in 25 nations. He is also a member of three different committees with the American Society for Testing and Materials (ASTM) dealing with floor slip resistance. He recently made substantial revisions and updates to the American slip and skid resistance test method – ASTM E303-22 – which was published by the ASTM in June of 2022. He is also a full member of the United Kingdom’s Slip Resistance Group (UKSRG), who helps create slip resistance test standards for the entire European Union as well as the United Kingdom.

John calibrates pendulum testers after having been trained to do so in the United Kingdom by a major pendulum manufacturer there. He has now calibrated pendulums for private corporations and governmental agencies in several countries.

PUBLICATIONS: “Specifying Anti-Slip Floor Coatings”, March 2020, pg. 24

“The New Slip Resistance Requirements in IBC,” July 2016, pg. 72.

Numerous educational blog posts published at

Numerous educational videos published at

Engineering Consultant and Expert Witness — Slip, Trip and Fall

Slip and Fall Expert Witness

Curriculum Vitae

Download his full Curriculum Vitae

Academic Background:  Ph.D., University of Sheffield, England
B.S., Pennsylvania State University

Recent Experience: Consultant/expert witness in slip/trip and fall litigation; experience in locations ranging from Japan and Guam to Bermuda. Project Manager and Principal Investigator of OSHA-driven one-man-year project to minimize slipping incidents on construction-site steel products. Laboratory and field testing of pedestrian surfaces for slip resistance. Consultant to Carnival Cruise Lines in slip reduction

Professional Affiliations: Member of eight national organizations, in two nations, relevant to slip resistance affiliations of pedestrian surfaces. Chairman, Ceramic Tile Institute of America’s Slip Resistance Committee

Member of American Society for Testing and Materials (ASTM) and American Society of Mechanical Engineers (ASME)

Publications:  Book, STOP Slip and Fall Accidents! 203 pp., Sotter Engineering Corporation, 2000,, ISBN 0-9676030-0-5

“Specifying Anti-Slip Floor Coatings”, March 2020, pg. 24

“How to Buy Flooring Having Sustainable Slip Resistance,” The National Hotel Motel Engineer Association magazine, Winter 2011

“How to Buy Flooring Having Sustainable Slip Resistance,” U.S. Government’s Center for Disease Control, NIOSH International Conference on Fall Prevention and Protection 2010 in Morgantown, WV on May19, 2010.

Resonant Combustion in Rockets,” Scientific American, December 1968

Author of over 35 papers, articles and other publications in technical trade magazines, international symposia, and archive journals. Includes several addressing pedestrian falling accidents

Registrations, Certifications:  Licensed as a Professional Engineer (Chemical) by State of California Board for Professional Engineers and Land Surveyors (current, since 1971), and (on as-needed basis) five other states.

Experience: More than 50 years in consulting and engineering. Slip-and-fall forensic consulting for both plaintiff and defense, in roughly equal proportions.