contradicts witness testimony, identifies the perpetrator(s), provides investigative leads, sheds light on
the perpetrator's methods (modus operandi), and demonstrates that a crime has occurred.33
iii. Digital Evidence Consideration
In this phase, the integrity of digital evidence is assessed by scrutinizing the digital forensics procedures
and tools utilized in obtaining the evidence, as well as the competence and qualifications of the digital
forensics experts involved in its acquisition, preservation, and analysis. This evaluation aims to ensure
that scientific principles were adhered to in the preservation, acquisition, and analysis of digital
evidence, and that standards were met in handling and examining it.
Digital forensics experts present testimony in court to elucidate their qualifications, explain the
workings of digital devices and ICT-related sources, outline the digital forensics process, justify the
selection of specific digital forensics tools, describe how digital evidence was preserved, acquired, and
analyzed, interpret the findings of analyses, assess the accuracy of these interpretations, and account
for any alterations to the data and their reasons.
The qualifications of digital forensics experts are also scrutinized to confirm the competency of
individuals handling and analyzing digital evidence. This competency is crucial to ensure the quality of
work products and install confidence in the results produced. While there are no universal competency
standards for digital forensics experts, their qualifications vary by country, and certification may or
may not be required depending on the jurisdiction. This phase evaluates whether experts possess the
necessary qualifications to act as expert witnesses and/or conduct examinations of ICT and ICTrelated data, and whether their competency has been verified and tested.34
iv. Digital Evidence Determination
In this phase, the authenticity, integrity, and reliability of digital evidence are evaluated based on the
assessment conducted in the previous phase. This includes verifying the use of forensically sound
methods and tools and relying on expert testimony to confirm the evidence's credibility. Admissible
digital evidence must establish relevant facts, remain unchanged throughout the forensic process, and
be supported by valid, peer-reviewed results. It's essential that interpretations of findings are unbiased,
with any errors or limitations disclosed. Overall, this three-phase model harmonizes legal and technical
33
34
US National Institute of Justice; 2004a; Maras, 2014
Brezinski and Killalea, 2002; US National Institute of Justice, 2004a; European Network of Forensic Science
Institute, 2015
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