Computer Forensics: Computer Crime Scene Investigation (With CD-ROM) (Networking Series)

The impartial computer forensics expert who helps during discovery will typically have experience on a wide range of computer hardware and software. It is always beneficial when your case involves hardware and software with which this expert is directly familiar. But fundamental computer design and software implementation is often quite similar from one system to another; and, experience in one application or operating system area is often easily transferable to a new system.

Unlike paper evidence, computer evidence can often exist in many forms, with earlier versions still accessible on a computer disk. Knowing the possibility of their existence, even alternate formats of the same data can be discovered. The discovery process can be served well by a knowledgeable expert identifying more possibilities that can be requested as possibly relevant evidence. In addition, during on-site premises inspections, for cases where computer disks are not actually seized or forensically copied, the forensics expert can more quickly identify places to look, signs to look for, and additional information sources for relevant evidence. These may take the form of earlier versions of data files (memos, spreadsheets) that still exist on the computer’s disk or on backup media, or differently formatted versions of data, either created or treated by other application programs (word processing, spreadsheet, e-mail, timeline, scheduling, or graphic).

Protection of evidence is critical. A knowledgeable computer forensics professional should ensure that a subject computer system is carefully handled to ensure that:

1. No possible evidence is damaged, destroyed, or otherwise compromised by the procedures used to investigate the computer.

2. No possible computer virus is introduced to a subject computer during the analysis process.

3. Extracted and possibly relevant evidence is properly handled and protected from later mechanical or electromagnetic damage.

4. A continuing chain of custody is established and maintained.

5. Business operations are affected for a limited amount of time, if at all.

6. Any client–attorney information that is inadvertently acquired during a forensic exploration is ethically and legally respected and not divulged.^[iv]

^[iv]Judd Robbins, “An Explanation Of Computer Forensics,” National Forensics Center, 774 Mays Blvd. #10-143, Incline Village, NV 89451, 2001. (©Copyright 2002, National Forensics Center. All rights reserved), 2001.