John H. Trestrail III, BS Pharm, FAACT, DABAT-E

Forensic & Clinical Toxicologist

ConsultantAuthor - Speaker


For Consultations and Speaking Engagments, contact

John Harris Trestrail III, BS Pharm, FAACT, DABAT-E

Forensic & Clinical Toxicologist – Consultant - Author – Speaker

Mr. Trestrail graduated with honors, obtaining a B.S. degree in Pharmacy, from Ferris State University, Big Rapids, Michigan, in 1967, where he was initiated into Rho Chi (Pharmaceutical Honor Society). In 2010, he received the Ferris State University's "Distinguised Alumnus Award".  From 1967-1968, he attended graduate school, at the College of Pharmacy, The Ohio State University, Columbus, Ohio, majoring in natural product chemistry. Mr. Trestrail’s public service experience was as a Volunteer with the United States Peace Corps, from 1968-1970, where he taught chemistry at the University of the Philippines College of Agriculture, in the Republic of the Philippines.

He is a practicing boarded toxicologist, and for many years, was a visiting instructor at the FBI National Academy in Quantico, Virginia, on the subject of murder by criminal poisoning.

Mr Trestrail is recognized internationally, as the foremost authority on criminal poisoning and murder by poison. For 33 years (1976-2009), he served as the Managing Director of one of the nation’s certified regional poison centers. He now serves as the Director of the Center for the Study of Criminal Poisoning. Since 1990, Mr. Trestrail’s seminars on"Murder by Poison!"and "Poisoners Throughout History", have been received with wide acclaim by audiences throughout the United States, Canada, Europe, and Asia.  Having presented over 300 seminars, he is a popular speaker.


Mr. Trestrail has served as an expert consultant in many criminal poisoning investigations, to law enforcement and attorneys. He has been honored as a Fellow by the American Academy of Clinical Toxicology, and is a Diplomate, by examination, of the American Board of Applied Toxicology. Mr. Trestrail founded the Center for the Study of Criminal Poisoning, as well as the Toxicological History Society, and has been featured in multiple episodes on The Discovery Channel, The History Channel, The Learning Channel, and PBS.


He was the project leader for the forensic research project that was able to resolve the key question in the famous British, 1910 Crippen murder case, using DNA comparisons with living exemplars, and took part in London, England, as a member of the research team, in the making of the PBS documentary “Secrets of the Dead: Executed in Error”, on this infamous poisoning murder case. He has been an active participant in the International Program on Clinical Safety, of the World Health Organization (WHO), working for the establishment of poison control services in the world's developing countries.


He is the author of the pioneering book Criminal Poisoning: An Investigational Guide for Law Enforcement, Toxicologists, Forensic Scientists, and Attorneys, published by Humana Press, in 2000 (2nd edition in 2007). He is also one of the co-editors of the popular book Toxicology Secrets, published by Hanley and Belfus Publishers, in 2001. His third book The Poison Quiz Book(2nd Ed.), was published by McGraw-Hill, in 2006.


Mr Trestrail is a member of the following professional organizations:

  • American Academy of Clinical Toxicology (AACT)
  • American Association of Poison Control Centers (AAPCC)
  • North American Mycological Association (NAMA) [Life Member]
  • Toxicological History Society (THiS)