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RF Investigation ServicesInterference · Location · Diagnostics
Expert witness services

RF & electronics expert witness.

Independent expert opinion and technical advisory for solicitors, barristers, insurers and the courts — in RF interference, GNSS, electronic surveillance, counter-drone technology and electronics disputes. Over 40 years' engineering experience. The expert's duty is to the court.

Areas of expertise

Technical opinion where the subject matter is RF or electronics.

RF & spectrum

RF interference

Source identification, propagation assessment and causal attribution — for disputes involving telecoms, broadcast, industrial RF, wireless systems and unlicensed transmission.

GNSS

Jamming & spoofing

Technical assessment of GPS/Galileo/GLONASS/BeiDou interference — for insurance claims, cargo-theft investigations, tracking disputes, and civil or criminal proceedings arising from GNSS-dependent failures.

Surveillance

Covert devices

Examination and opinion on covert audio and RF devices — device type, operating frequency, range, and whether a signal is consistent with a known surveillance technology. For espionage, privacy and criminal matters.

Counter-UAS

Drones & counter-drone

Opinion on drone detection systems, drone-incident investigations, and the capabilities and limits of counter-UAS technology — for incidents at prisons, airports, events and critical infrastructure.

Electronics

Systems disputes

Opinion on the design, function, failure or specification of electronic systems and components — for product liability, contract disputes and insurance assessment of electronics failures.

Wireless security

Alarm & access systems

Vulnerability of wireless alarm, access-control and security systems to jamming, replay or signal manipulation — for insurance disputes following alleged system defeat, and installer negligence claims.

Services for legal proceedings

From early review to the witness box.

Advisory

Preliminary technical review

An early-stage confidential advice note to help assess the merits of a technical argument and identify what evidence is needed — not a formal Part 35 report.

CPR Part 35

Expert witness report

A formal written report for civil proceedings, compliant with CPR Part 35 and its Practice Direction — opinion, reasoning, evidence base, declaration and statement of truth.

SJE

Single joint expert

Available to act as single joint expert where both parties agree, providing one independent opinion to the court.

Hot tubbing

Concurrent evidence

Available to give concurrent expert evidence alongside the opposing expert under judicial questioning, where the court directs.

Joint statements

Expert meetings

Participation in without-prejudice expert discussions and production of a joint statement of agreed and disputed technical issues.

Counsel support

Technical support to counsel

Review of opposing expert reports, drafting technical questions for cross-examination, and attendance at trial as technical advisor.

Criminal proceedings

Prosecution or defence

Expert opinion is available in criminal proceedings where the technical subject matter falls within the areas above. Instructions are accepted from both prosecution and defence. Criminal reports are prepared in accordance with Criminal Procedure Rules Part 19.

Independence & conflicts

Disclosed openly, managed properly.

Glenn Darien is also director of K9 Electronics Ltd, a manufacturer of RF and counter-UAS systems. This is disclosed openly because transparency, not silence, is what protects the independence of an opinion.

Duty to the court

Overriding obligation

Expert witness work is undertaken as a separate, independent activity. The expert's overriding duty is to the court, not to any instructing party or commercial interest, as required by Part 35.

Conflicts

Checked on every instruction

A conflicts check is carried out on receipt of each instruction. Any matter touching K9's commercial interests, customers or products is declined or disclosed immediately.

Depth

The reason for the expertise

That same manufacturing background is what underpins the technical depth of the opinion — direct engineering experience with the systems in question, transparently managed.

Qualifications & experience

Glenn Darien

Over 40 years' professional experience as an RF and electronics engineer, and founder and director of K9 Electronics Ltd, a UK-registered defence electronics manufacturer holding UK export control licensing (ECJU/SPIRE) and supplying counter-UAS, GNSS and RF systems to military and government customers.

His background spans RF systems design, signal-chain engineering, firmware development, interference investigation and spectrum analysis, with direct engineering experience of the technology underlying GNSS jamming and spoofing, wireless surveillance, counter-drone RF architectures and industrial electronics — experience that is engineering-led, not theoretical.

Compliance with Part 35 CPR

All expert reports for civil proceedings include the declaration required by Practice Direction 35 — that the expert understands and has complied with their duty to the court, and that the opinions are independent regardless of the instructing party — together with a statement of truth.

Practical matters

How instruction works.

Coverage

England & Wales

Based in the East Midlands, one hour from London. Available for court attendance across England and Wales, with site visits throughout the UK.

Fees

Hourly, agreed in writing

Charged at an hourly rate for all work — review, report, meetings, travel and court attendance. A fee estimate is provided on receipt of instructions and papers, and fees are agreed in writing before work begins.

Conflicts

Checked & disclosed

A conflicts check is carried out on receipt of each instruction; any potential conflict is disclosed immediately.

Turnaround

Confirmed at instruction

Availability and report turnaround are confirmed at the point of instruction. Urgent instructions are accommodated where possible — please flag at first contact.

Curriculum vitae

A full CV is available on request for instructing solicitors.

Request CV
Enquiries

Instructing parties welcome.

Please outline the matter, the subject area, and the court or proceedings involved. All enquiries are confidential.