The Internet of Things as a Witness: Evidence from Smart Homes and Wearables

The most honest witness at many modern scenes never intended to testify. A smart speaker records ambient sound because that is how it hears its wake word. A fitness band logs heart rate and location continuously because its owner asked it to. A connected doorbell archives motion-triggered video because the homeowner wanted parcel alerts. When an offence occurs within range of these devices, their routine records become the closest thing to a neutral account of what happened.

The pattern is well established abroad. In one American prosecution, a man described frantically retrieving belongings from a house fire; his pacemaker's stored data told a different story, and the discrepancy became the centre of the case. A murder investigation in Arkansas turned on audio preserved by a home speaker that nobody knew was recording. Indian investigations now meet the same category of evidence routinely, from smart homes in metropolitan buildings to connected-vehicle telematics in accident cases.

What makes device records different

• They are incidental. The owner created them for convenience, not for court, so there is no narrative bias; but there is also no custodian who thought about accuracy.
• They live on someone else's infrastructure. The complete copy is usually on the manufacturer's cloud, in another jurisdiction, governed by another country's disclosure process.
• They are sensor-mediated. A device records what its sensors registered, which is not the same as what happened. A heart-rate spike has many causes; a GPS point is an estimate.
• They are short-lived. Many devices overwrite their own logs, so preservation is a race against the device's housekeeping, not the defendant's lawyers.

Getting the record into court

Legally, an IoT record is an electronic record like any other. Under the Bharatiya Sakshya Adhiniyam, the successor to the Indian Evidence Act, it enters through the electronic-records route in Section 63, with a certificate identifying the record and the system that produced it. The difficulty is practical. The certificate must come from a person in a responsible official position in relation to that system, and for cloud-hosted data that means engaging the manufacturer's disclosure process early. An export that arrives six weeks later, without provenance documentation, satisfies nobody.

Interpretation is harder than admissibility. The device's clock was four minutes off; does the timeline still hold? A GPS path and a toll-plaza record disagree; which does the court prefer, and on what basis? When a sensor's documented failure modes map neatly onto the accused's account, does that corroborate the account or undermine the sensor? Answering these questions requires the examiner to testify about the device's operation with the rigour traditionally reserved for laboratory methods. It is why device forensics is hardening into a discipline of its own, distinct from classic computer forensics.

The privacy bill

The same records that exculpate the innocent expose everyone nearby. Continuous health and location logging means an investigation touching one person sweeps in the routines of a whole household. India's Digital Personal Data Protection Act, 2023 now frames how personal data is handled, and investigators, service providers, and courts are still calibrating how disclosure, proportionality, and data minimisation apply to devices that were only trying to count steps.

For practitioners the takeaway is a habit rather than a doctrine. Identify the devices in an incident's orbit within the first hours. Preserve before they overwrite. Document the sensor's limitations as carefully as its data. The devices will keep testifying either way; the profession's job is to make sure they are understood.