An impartial computer forensics expert who helps during discovery will typically have experience on a wide range of computer hardware and software.  This experience will prove fruitful when your case involves hardware and software with which this expert is directly familiar.  Fundamental computer design and software implementation is quite similar from one system to another in most circumstances, and experience in one application or operating system area is often easily transferable to a new system.

Computer evidence, unlike paper evidence, can often exist in many forms, with earlier versions still accessible on a computer disk or backup media.  Being familiar with the existence of different sources, even alternate formats of the same data can be discovered.  The discovery process can be conducted effectively by a knowledgeable expert identifying more possibilities that can be requested as possibly relevant evidence. In the process of an on-site premises inspection, for cases where computer disks are not actually seized or forensically copied (see below), a forensics expert can more quickly identify places to look, signs to look for, and additional information sources for any relevant evidence.  These may consist of earlier versions of data files (eg. 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 (eg. word processing, spreadsheet, e-mail, timeline, scheduling, or graphic).

The protection of the evidence is critical.  A computer forensics professional will ensure that a subject computer system is carefully handled to ensure that:

• no possible evidence is damaged, destroyed, or otherwise compromised by the procedures used to investigate the computer.
• a continuing chain of custody is established and maintained.
• no possible computer virus is introduced to a subject computer during the analysis process.
• extracted and possibly relevant evidence is properly handled and protected from later mechanical or electromagnetic damage.
• any client-attorney information that is inadvertently acquired during a forensic exploration is ethically and legally respected and not divulged.
• business operations are affected for a limited amount of time, if at all.

A computer forensics specialist will take careful steps to identify and attempt to retrieve any possible evidence that may exist on a subject computer system.

• Protect the subject computer system during the forensic examination from any possible alteration, damage, data corruption, or virus introduction.
• Discover all files on the subject system.  This includes existing normal files, deleted yet remaining files, hidden files, password-protected files, and encrypted files.
• Recover all, or as much as possible, of discovered deleted files.
• Reveal, to the fullest extent, the contents of hidden files as well as temporary or swap files used by both the application programs and the operating system.
• Access (if possible and legally appropriate) the contents of protected or encrypted files.
• Analyze all possibly relevant data found in special (and typically inaccessible) areas of a disk.  This includes but is not limited to what is called 'unallocated' space on a disk (currently unused, but possibly the repository of previous data that is relevant evidence), as well as 'slack' space in a file (the remnant area at the end of a file, in the last assigned disk cluster, that is unused by current file data, but once again may be a possible site for previously created and relevant evidence).
• Print out an overall analysis of the subject computer system, as well as a listing of all possibly relevant files and discovered file data. Further, provides an opinion of the system layout, the file structures discovered, any discovered data and authorship information, any attempts to hide, delete, protect, encrypt information, and anything else that has been discovered and appears to be relevant to the overall computer system examination.
• Provide expert consultation and/or testimony, as required.

Many types of criminal and civil proceedings can and do make use of evidence revealed by a computer forensics specialist:

• Criminal Prosecutors use computer evidence in a variety of crimes where incriminating documents can be found, such as homicides, financial fraud, drug and embezzlement record-keeping, and child pornography.
• Civil litigations can readily make use of personal and business records found on computer systems that may contain evidence of fraud, divorce, discrimination, and harassment.
• Insurance Companies may be able to mitigate costs by using discovered computer evidence of possible fraud in accident, arson, and workman's compensation cases.
• Corporations often hire computer forensics specialists to ascertain evidence relating to sexual harassment, embezzlement, theft or misappropriation of trade secrets and other internal/confidential information.
• Law Enforcement Officials frequently require assistance in pre-search warrant preparations and post-seizure handling of the computer equipment.
• Individuals sometimes hire computer forensics specialists in support of possible claims of: wrongful termination, sexual harassment, or age discrimination.