App-Based Telematics Review in Alleged Drink Driving Incident

In a case involving a young driver accused of driving while unfit through drink, IntaForensics was instructed to examine data from an insurance telematics app installed on the defendant’s mobile phone. Our task was to assess whether the app could reliably identify the defendant as the driver and to evaluate the movement data captured around the time of the incident. Our findings were presented in an expert report and provided critical context in support of the defence legal team.

The incident involved a car that had reversed into another vehicle on a residential street. The prosecution alleged that the defendant had been driving under the influence of alcohol. In contrast, the defence maintained that the car rolled backwards unintentionally after a passenger released the handbrake in error. 

The defendant had been insured through a provider offering reduced premiums to young and inexperienced drivers, conditional on the use of a behaviour-monitoring mobile app. This app, installed on the user’s phone, tracked aspects of driving performance and journey history. Given the nature of the allegation, the app data became a focal point of the investigation. 

The prosecution viewed the app data as a potential source of evidence to support the claim that the defendant had been driving at the time of the incident. However, the accuracy, reliability, and interpretation of this data were central to the defence case. The question was whether the app could definitively determine who was driving, their location in the vehicle, and whether the car’s movement aligned with the allegation. 

Our challenge was to assess how the app functioned, identify any technical or operational limitations, and explain the degree to which the data could be considered evidentially sound.

IntaForensics conducted a full analysis of the app’s data, operational design, and recorded journey history. Our work included the following:

Technical analysis of app functionality
We reviewed the structure and logic of the app, identifying how it collected, stored, and interpreted GPS and motion data, as well as what user interaction was required for accurate logging.

Assessment of device dependency
We evaluated how the app’s operation relied on the mobile device being powered on, connected to the mobile network, and having sufficient battery. We highlighted how loss of power or network signal could compromise data recording.

Evaluation of location accuracy and tagging limitations
We explained the limitations of GPS data, including its potential margin of error. We also noted the app’s reliance on the user to manually declare whether they were a driver or passenger, and the lack of any way to verify the user’s physical position within the vehicle.

Extraction and review of movement data
We extracted location data recorded by the app on the date of the incident and plotted the movement history to assess what could be reliably inferred. The data showed that the device — and therefore the app — had remained largely static in the same street for an extended period.

Expert witness report
Our findings were presented in a formal expert witness report, detailing the app’s limitations, the context of the data, and the extent to which the information could support or contradict the prosecution’s claims.

The report provided a clear understanding of the technical framework underpinning the app and placed proper boundaries around the interpretation of its data.

Our expert analysis confirmed that while the app recorded location data, it could not determine whether the user was in the vehicle, nor could it reliably identify who was driving at the time. The app’s reliance on GPS, user input, and the operational state of the mobile device introduced several layers of uncertainty. 

The location data extracted from the app confirmed that the device had remained stationary in the relevant street for a prolonged period, which aligned with the defence’s account. However, due to the limitations in the app’s design, no definitive conclusion could be drawn about the user’s role or actions at the moment of the incident. 

This case illustrates the need for caution when interpreting behavioural or location data from mobile apps. While such tools offer general insights, they are not designed as forensic-grade evidence sources unless properly validated and contextualised.

Contact IntaForensics to discover how our digital investigation services can support your case with integrity, accuracy, and expert insight. Get in touch at sales@intaforensics.com or call us on: 0247 77 17780.