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Forensic Examination of Digital Evidence: A Guide for Law Enforcement

NCJ Number
199408
Date Published
April 2004
Agencies
NIJ
Publication Type
Policy/Procedure Handbook/Manual
Grant Number(s)
1999-IJ-R-094
Annotation
This document presents a guide for use by law enforcement officers responsible for the examination of digital evidence.
Abstract
The guide deals with common situations encountered during the examination of digital evidence. It is a guide agencies can use to help them develop their own policies and procedures. When dealing with digital evidence, general forensic and procedural principles should be applied. Actions taken to secure and collect digital evidence should not affect the integrity of that evidence. Persons conducting an examination of digital evidence should be trained for that purpose. Activity relating to the seizure, examination, storage, or transfer of digital evidence should be documented, preserved, and available for review. The examiner should be cognizant of the need to conduct an accurate and impartial examination of the digital evidence. Digital evidence is fragile and can be altered, damaged, or destroyed by improper handling or examination. Examination is best conducted on a copy of the original evidence. The original evidence should be acquired in a manner that protects and preserves the integrity of the evidence. The purpose of the examination process is to extract and analyze digital evidence. Extraction refers to the recovery of data from its media. Analysis refers to the interpretation of the recovered data and putting it in a logical and useful format. Actions and observations should be documented throughout the forensic processing of evidence. Agencies likely to handle digital evidence should identify appropriate external resources for the processing of digital evidence before they are needed. These resources should be readily available for situations that are beyond the technical expertise or resources of the department. Agencies should also develop policies and procedures to ensure compliance with Federal, State, and local laws. The basic steps to conduct a computer forensic examination are policy and procedure development, evidence assessment, evidence acquisition, evidence examination, and documenting and reporting. 8 appendices
Date Created: May 28, 2004