Forensic Toxicology


Toxicology is the study of adverse effects of drugs and chemicals on living organisms. The discipline is divided into several major areas--Forensic, Clinical and Environmental. Forensic Toxicology applies toxicology to matters of law, to assist the courts in reaching verdicts that are in keeping with the facts. Put another way, forensic toxicology is involved with the medicolegal aspects of the use of drugs and chemicals that are harmful to man combining analytical chemistry and fundamental toxicology. 


The Toxicology Unit identifies and quantifies (determines the amounts of) drugs, alcohols, and poisons in biological samples such as blood, urine, or tissue. The information is used by law enforcement and the courts to help determine if laws have been broken and/or if criminal charges are warranted. For instance, when there is cause to believe that a person may have been under the influence of alcohol and/or drugs, blood and urine samples are submitted for analysis. Forensic toxicologists also assist in postmortem investigations to establish the cause or circumstances of death.


Toxicology testing can be as routine as a single blood alcohol test or as complex as determining concentrations of a half dozen drugs and their metabolites in a single sample. The level of testing depends on the case and the type(s) of sample(s) submitted.


Services Provided


Toxicology Analysis Provided

The Toxicology Unit provides qualitative and quantitative analysis using instrumental methods to identify compounds. Instrumental analysis includes Headspace-Gas Chromatography (HS-GC), Enzyme Linked Immunosorbent Assay (ELISA), Gas Chromatography/Mass Spectrometry (GCMS) and Liquid Chromatography-Mass Spectrometry-Mass Spectrometry (LCMSMS). 


Toxicology Kits Available

The Medical-Forensic Drug Facilitated Sexual Assault (DFSA) Kits are available free of charge to law enforcement from Document Sales  for the collection of toxicology (blood and urine) samples from sexual assaults for submission to the Toxicology Unit at the Wisconsin State Crime Laboratory.  



Toxicology Evidence Submission Guidelines, Rev. 10/2023


Toxicology FAQs

Reference laboratories


Contact Information 

For questions regarding Toxicology, refer to the contact information for the lab in your service area.