forensic accounting is accounting that is suitable for legal review, offering the highest level of assurance, and including the now generally accepted connotation of having been arrived at in a scientific fashion. That is, forensic accounting is sufficiently thorough and complete so that an accountant, in his/her considered independent professional judgement, can deliver a finding as to accounts, inventories, or the presentation thereof that is of such quality that it would be sustainable in some adversarial legal proceeding, or within some judicial or administrative review.
Findings are based upon the scientific detection and interpretation of the evidences of phenomena introduced into the books and records of an accounting system (expansively defined) and the effects of such phenomena upon the accounts, inventories, or the presentation thereof. (Alternatively, if there is no impact on an accounting system, there is no accounting evidence, nor is there any effect upon the accounts, inventories, or the presentation thereof; and such situations are not within the realm of forensic accounting.)
The primary orientation of forensic accounting is explanatory analysis (cause & effect) of phenomena - including the discovery of deception (if any), and its effects - introduced into an accounting system domain. The primary methodology employed by forensic accountants is objective verification. Since all professional accountants operate within a commercial legal environment, all professional accountants are, in a sense, forensic accountants.
What distinguishes forensic accounting in common parlance, however, are the engagements. That is, when a professional accountant accepts an engagement where they anticipate that their finding or analysis may be subject to adversarial or judicial scrutiny or administrative review, the professional accountant seeks a level of evidentiary detail and analytical precision which will be sustainable within the legal framework of such scrutiny or review.