Pathologist is a physician who interprets and diagnoses the changes caused by disease in tissues and body fluids. S/he is an expert witness who determines through laboratory medicine the causes of tissue disease.
The following is an example of a case law defining pathologist:
‘A pathologist is a physician who examines tissues and is responsible for the accuracy of laboratory tests. [State v. Erickson, 2011 Wisc. App. LEXIS 21 (Wis. Ct. App. 2011)]