IT Forensics · Courts
How should we deal with conflicting digital traces?
Digital evidence is not always consistent. A log may indicate one time, whilst a database may show another. Two analysis programmes may interpret the same data set differently. A file may be present in a backup but missing from the current file system.
Such inconsistencies are no reason to halt the investigation. They are themselves the subject of the investigation. The key is to identify their technical cause: differing temporal semantics, synchronisation issues, parser errors, corrupted data, differing data states or genuine inconsistencies.
A good expert report does not conceal such points. It shows the court which sources are consistent and which are not, and how this affects the determination of the issue in dispute.
The actual question of evidence
Which source takes precedence in the event of a conflict?
There is no general rule stating that a particular tool or database is always „more accurate“. The factors assessed are the mechanism of origin, proximity to the original event, integrity and corroboration by independent evidence.
In the case of key findings, we check the raw data where necessary or use a second recognised method to rule out any parser or display errors.
Where the limits of what can be said lie
If a contradiction cannot be resolved, the remaining uncertainty must be included in the result.
Why LanCologne?
In the case of court-ordered investigations, it is not a matter of which analysis programme displays a match first. What matters is whether the question of evidence can be answered on a technical basis and whether that answer stands up to independent scrutiny.
We adopt an open-minded approach, document the origin of key findings and examine alternative technical explanations. The actual analysis is always carried out on a forensic copy or a dataset that has been securely preserved as evidence. Originals are not examined directly unless absolutely necessary. Where live procedures are technically necessary, any changes that may result from them are explicitly documented.
Depending on the research question, key findings are verified either using a second method appropriate to the subject matter or directly on the basis of the underlying raw data. The tools used for this purpose depend on the evidence and the research question. The key factors are the suitability, professional recognition and traceability of the method – not a product name.
Our report distinguishes between factual findings, technical assessments and remaining uncertainties. A negative finding is justified just as carefully as a positive one.
How we handle court-ordered assignments
How we work – from the court order to the response
We first check whether the matter falls within our area of expertise, what facts the court is basing its decision on, and whether the content or scope of the assignment is clear. If there is any doubt, the court will seek clarification. This is in accordance with Sections 404a and 407a of the Code of Civil Procedure (ZPO).
Any reasons that might give rise to doubts as to impartiality are examined before the substantive investigation begins and, where appropriate, disclosed to the court.
Devices, data storage media, backups and files provided are identified and documented. The status at the time of the investigation is recorded.
Where technically feasible, a forensic copy or image is created. Hash values and other integrity checks are used to ensure unambiguous identification. The original is retained for future verification.
We determine which evidence would support the alleged event, what contradictory findings are conceivable, and which alternative technical explanations need to be examined.
Only those artefacts which have professional evidential value in relation to the issue in question are examined. Automatic matches are not accepted without verification.
Findings relevant to the decision are – where necessary – cross-checked using a second recognised method, a different technical approach or directly against the raw data.
We explicitly examine what conclusions must not be drawn from the data. We identify missing data, possible deletions, technical limitations, incomplete extracts or contradictory evidence.
The final conclusion is drawn from the documented findings. It is not stated in stronger terms than the data permit.
The main text remains accessible even to those without a background in digital forensics. The technical appendix contains the information required by an independent IT forensic expert to carry out a technical review or prepare a counter-report.
Legal framework
Sections 407a, 411 and 412 of the Code of Civil Procedure (ZPO). Section 412 of the ZPO allows the court to order a new expert opinion if it considers an existing one to be inadequate.
The expert provides the factual basis for the case. The legal assessment and the final evaluation of the evidence remain the responsibility of the court.
Frequently Asked Questions
LanCologne – IT Forensics for the Courts
Do you require an independent technical investigation into a matter of evidence for court proceedings? LanCologne examines digital evidence objectively, transparently and in a reproducible manner. We document both positive findings and the absence of evidence, as well as technical limitations, in such a way that the conclusions remain comprehensible to the court and verifiable by an independent IT forensic expert.
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