“Smart wearable technologies or wearable devices are used to describe seamlessly embedded portable computers and advanced electronics that can be worn on the body and allow for interactions between users and a smart environment.” ^[1]

Alternative definitions include:

“Body-worn sensors, also called wearable sensors, are small devices that people can carry around while performing their daily activities.”^[2]

“The terms ‘wearable technology’, ‘wearable devices’, and ‘wearables’ all refer to electronic technologies or computers that are incorporated into items of clothing and accessories which can comfortably be worn on the body.” ^[3]

Wearables capture data in real-time, recording the choices people make in their daily lives. Wearables include body-worn to hand-held devices for the collection of data and better understanding of the individual and their environment.^[4] How data is captured, stored and transferred to third-party systems is unique to each manufacturer,^[5] but a common method of data transfer from the worn device to an application or server is through Bluetooth in the first instance.

As technology evolves, it is increasingly being incorporated into various forms of wearables. Specific examples include watches, eyewear, fitness trackers, clothing, cameras as well as various forms of medical devices.^[7]

Wearable technology can capture data the user may be unaware of and act as a sixth sense as well as recording the choices a person makes on a daily basis.^[8] The devices have intelligent functionality and may be part of a smart system connected by other technology. ^[9].

Wearables have a range of categories^[10], but are divided into four general categories by the International Electronical Commission (IEC)^[11], these being:

1. Near-body electronics. Device does not contact the external surface of the organism directly.
2. On-body electronics. Device contacts the external surface of the organism directly.
3. In-body electronics. Devices located internal to an organism.
4. Electronic textiles. Fabrics or textile-based electronic devices and components.

Wearable technology can be used to monitor human behaviour as people undertake different activities during their day. The sensors embedded in the technology can track the behaviour of the individual and connect to social media where it can be available to the public or restricted viewing. An example is the use of fitness trackers.^[12] which records physical activity and can chart activity and progress over time. This can be shared with others as the user decides.

Medical technology may be used as wearables rather than implanted into the human body as a non-invasive way of collecting accurate medical data. The biosensors can be used to prevent disease, obtain an early diagnosis of an illness and facilitate a treatment plan for the patient.^[13] Specific examples may also include pain management, psychological tracking, and the monitoring of various states such as glucose, sleep or brain activity.^[14] An evolving technology is electronic skin patches that mimic human skin and can be glued directly onto the body such as an arm. The patches can be connected to a smartphone and data gathered transferred to cloud devices.^[15]

The technology within the device measures the relevant signals being generated by the user via microphones, sensors and sometimes cameras with the sensors being located in wristbands, necklaces, chest belts and as technology evolves, sensor clothing.^[16] Technology is continually evolving, and wearable technology is developing new categories of use for multiple markets.

The data that may be collected by wearables includes user activity, location, voice and medical data.^[17] The data is transferred via technology such as Bluetooth to a connected smartphone to the applications developer’s smart servers where it can be made available to social media^[18] depending on the End User License Agreement (EULA) to the application developer or other party such as a medical professional. Alternatively, it can be analysed to understand clients’ uses of the device including their location.

Examples of what wearable devices record include changes in a user’s levels of stress, their emotional state including fear, anger, sadness, mood swings, the level of physical activity being undertaken and may include detailed information on their physical location.^[19] They can also record the skin conductance level (helps to determine mood) and temperature to help analyse their moods and feelings.^[20] A user’s heart rate can be recorded and stored along with their physical location and the psychological wellness of the individual can be mapped.^[21], ^[22]

Data may be transferred from the wearable for permanent storage. It may be linked to a computer or smartphone before being forwarded through a proprietary or third-party application for permanent data storage.^[23] In the Apple environment, data may be transferred through a native Apple application, or through a third-party application such as a fitness tracker downloaded through the Apple store.

The data generated in the device may not be transferred in real time. This form of data is also in its raw format which is not necessarily human readable in a convenient format.^[24]

Questions as to what format data is stored and whether there is a time lag from the time the data is created within the device to when it is forwarded to the data warehouse can only be answered by researching a device at the time of an inquiry, and if necessary, reaching out to the manufacturer for information.

As the following list shows, wearables contain sensors that are highly sensitive to the environment the wearer is operating within and their activity. They even record a lack of activity. They can collect and present raw data such as the recording of the wearer’s heart rate, body temperature, and stress levels or analyse the raw data and produce an output such as an assessment of the quality of a person’s sleep.

The various types of sensors are listed in the following table.^{[25] [26]}

Wearable Technology Sensors

These sensors capture a wide range of data. In some instances, they relate to specific industries such as mining, construction or health. Mardonova & Choi identifies a smart safety helmet that incorporates sensors to detect methane and carbon monoxide gases.^[27]ps://teslasuit.io/blog/detailed-wearables-classification-by-teslasuit-team/

As with all technology, the investigator has to be aware this form of technology exists, what its function is, what data it collects and how it may be beneficial in their investigation. This is because despite the intention of the technology developers; criminals will find a way to misuse it to advance their purpose. Alternatively, the device may accumulate evidence that the device owner is unaware of. Subsequently, the investigator needs to have a basic understanding of the functions of this technology, how it works and what it can reveal in an investigation.

The wearable/implantable technology may be evidence to link a suspect to the crime or evidence of a crime being committed against another. An example of this is in the case of a homicide where the pacemaker or fitness tracker records the exact time of death of the wearer and the activity of the heart in the direct moments leading to death.

“An implantable sensor is a type of implantable device that contains one or more sensing elements, such as strain gauges or pressure sensors, which perform localized measurements.” ^[31] 

Implantable devices are particularly relevant to the field of medicine as devices can record critical activity such as the performance of the heart, giving the patient’s medical professionals access to timely and accurate data upon which to base their diagnosis and future treatment. The technology installed can be externally accessed and may have storage capability.

The Australian Therapeutic Goods Administration (TGA) of the Department of Health and Aged Care provides the following definition of a medical implantable device.

Active implantable medical device or AIMD means an active medical device, other than an implantable device, which is intended by the manufacturer: ^[32]

(a) either:

(i) to be, by surgical or medical intervention, introduced wholly, or partially, into the body of a human being; or

(ii) to be, by medical intervention, introduced into a natural orifice in the body of a human being; and 

(b) to remain in place after the procedure. 

The TGA provides examples of implantable devices such as pacemakers/defibrillators, cardioverter-defibrillators, cardiac monitors, cochlear implants, brain electrical stimulation systems, and spinal cord stimulation systems.^[33]

Medical implants can communicate to a mobile device and the data recorded can be uploaded to a cloud computing server for storage and analysis as required.^[34] This would be very beneficial to a medical practitioner who wishes to remotely monitor the progress of a vulnerable patient and have a full understanding of their health prior to the next consultation. They can also be alerted in real-time to a potentially fatal action such as a dangerous rise in the blood pressure of a patient.

An example of a non-medical implantable is a microchip the size of a grain of rice inserted into the body that uses Near Field Communication (NFC) technology to communicate with reader terminals in stores and other locations.^[35] This may be into the web of the hand which can be used to make cashless payments at Point-of-Sale terminals. As storage capacity and technology increase, other information such as a driver’s licence, personal identification and items of value to the person may be recorded on these implantable storage devices.

Implants can also include tattoos which use special inks that are capable of storing data. Medical researchers have developed smart ink which changes color as a warning if a person has certain health problems such as diabetes or is dehydrated.^[36]

This is particularly valuable for the criminal as there is no outward sign that they have a data storage device within the palm of their hand or tattoo containing the important data you are looking for. You could shake their hand and not be aware your hand is next to the critical evidence.

“A smartwatch is a personal computing device equipped with multiple functions (i.e. making phone calls, texting, timekeeping, health activities, and fitness tracking) that is worn on the wrist.” ^[37]

Smartwatches may connect online through Bluetooth or Wi-Fi depending on the settings the user initiates. Bluetooth connects to a linked mobile device and communication then travels through that device.^[38]

Smartwatches may be directly connected to a server or operate through a connection to a smartphone which in turn, connects to the watch’s server and stores the recorded data. Alternatively, the data recorded by the watch may be stored on the phone only. This depends on the manufacturer of the device.

As an example of features smartwatches provide users, Apple lists the features of a selection of their watches, beyond telling the time and displaying messages.

These features include:^[39]

• • • Apple Pay.
    • App store connection.
    • Blood oxygen.
    • Call and text.
    • Crash detection.
    • Electrocardiogram.
    • Emergency SOS.
    • Heart health notifications.
    • Fall detection.
    • Fitness tracker.
    • Maps.
    • Music.
    • Siri.
    • Sleep tracking.
    • Temperature sensing.

These watches are designed to be user-friendly and seamlessly integrate with a smartphone.

Smart watches and smart bands are different as the former contains an Operating System that can allow the installation of third-party applications at the direction of the owner. This is not the case with smart bands.^[40]

Watches contain a measurement of a person’s pulse as do fitness trackers. One possible investigative technique is to monitor the person’s pulse during an interview and note the times when they appear to be experiencing stress or reactions when key questions are asked. This evidence can be captured on the device itself should it be seized post-interview and the heart rate measured against the key times recorded. Alternatively, if the person has an open-source fitness tracker application linked to an online cloud account there may be the opportunity to view the heart rate of the person in the interview, during the interview, or afterwards.

Whether this is legal or admissible evidence will depend on your jurisdiction and its laws, however, if this data is available, check the legality of accessing it and at least be aware of its value for investigation intelligence.

With the Apple smartwatch connected to the Apple phone, the health data recorded will be linked to the health application if the user has configured this setting. Apple may record general data for the use of the device owner or, with the owner’s permission, allow anonymised data to be shared for medical research. Apple Health allows external applications developed for Nike, Fitbit and RunKeeper fitness applications to operate on their devices.^[41]

Health apps can also record the sleep pattern of a person. The Apple sleep app identifies whether a person is asleep or not and when they move from a light to a deep sleep and the total sleep and awake time.^[42]

Besides Apple there are multiple smartwatch manufacturers including ASUS, Fossil, Huawei, Fitbit, Polar and Samsung, so there are many potential sources of evidence from smartphones connected to a smartphone.

The Huawei smartwatch GT2, for example, incorporates a fitness tracker storing GPS location and heart rate. It also contains Bluetooth connectivity to a smartphone, in-device music, sleep tracking, activity monitoring, email, calendar, social media apps, weather, alarm, timer, stopwatch, torch and pressure monitoring. In effect, a watch such as this incorporates many of the features of a smartphone that it can pair with. It also tells the time.^[43]

Google has an Operating System (OS) called Wear OS that controls the products of other manufacturers of smartwatches such as Fossil, TicWatch and Huawei.^[44] Wear OS contains many of the features already identified as well as Google Pay, Google Maps, Gmail and numerous other applications.^[45]

Fitbit operates the Fitbit OS and Samsung the Tizen OS has its own operating system.^[46]

Of particular note to the investigator may be the data contained in the Google Fit application which is needed to transfer the data collected from the smartwatch or fitness tracker to the Google data storage facility.^[47] Google Fit supports Nike, Adidas, Ziami, HTC, Motorola and LG products. Data generated may be viewed on the Google Fit website or within the app.^[48]

The next smart device to be examined is the fitness tracker. You will note there are a lot of similarities between smartwatches and fitness trackers, however, it is worth examining the trackers to be aware of how they work and what they uniquely collect and store.

Fitness trackers are connected to a mobile device via a Bluetooth connection with the data generated within the fitness tracker synchronized to the mobile device.^[49] The data may be synchronized to a cloud account maintained by an application associated to the tracker.

Like smartwatches, fitness trackers can monitor GPS location of the wearer, heart rate, calories burnt in activity, steps taken, speed and the time of movement, monitor sleep patterns, gyroscope for measuring rotational motion, skin response sensors and alerts to advise when activity goals have been reached.^[50] It has been determined that the analysis of a selection of data such as heart rate, respiration or skin conductance can be used to track the moods and feelings of individuals.^[51]

Fitness monitors are often used to upload information such as workout data to the manufacturer’s cloud servers so the user can monitor their activity and progress. It can also be used in applications where user activity can be compared to others.

Manufacturers of fitness trackers include FitBit, Garmin and Polar. Most fitness trackers include an Operating System that allows for the installation of third-party applications.^[52]

An example of a fitness tracker is the Fitbit Versa 2 health and fitness smartwatch which contains heart rate monitoring, sleep score, Amazon Alexa connectivity with control over the smart home, real-time exercise statistics, music, apps, smartphone notifications, sleep tracking, personalized workouts, steps tracker, clock, distance travelled, calories burnt, floor climbed, hourly activity and stationary time, pace of movement with Bluetooth connectivity connecting to a smartphone.^[53]

Fitbit has an application that can link to the data mentioned in the previous paragraph and provide general information on activity, exercise, heart rate and sleep as measures of the impact of the user’s lifestyle on their health.^[54]

As we can see with the multitude of features of the fitness tracker, it is very closely associated with a smartwatch with many of the features recorded being similar. It is expected that this list of features will expand as technology evolves.

With the wide range of manufacturers making wrist wearable smart devices meeting market demand, some sensors are standard across the devices and others are rarer. The most common sensors capture the following data:^[55]

• • • Altimeter.
    • Ambient light.
    • Barometer.
    • Calories.
    • Distance.
    • Galvanometer.
    • Global Positioning System.
    • Gyroscope.
    • Heart rate.
    • Magnetometer.
    • Microphone.
    • Pedometer.
    • Sleep analytics.
    • Thermometer.
    • Ultraviolet light sensor.
    • Walking speed.

Smart clothing is a developing trend where major manufacturers are assessing the potential for their products to be connected to smart devices. Smart clothing has conductive fibers built into or attached to the item of clothing.  Examples of smart clothing include shoes, socks, sleepwear, active and casual wear. Examples of designers who have produced items of smart clothing include Tommy Hilfiger, Levi’s and Ralph Lauren.

The fabric used in smart clothing can determine medical data, emit vibrations, display custom messages, block sunlight and change colours.^[56]

An example of the value of wearable technology such as smart clothing is in the mining industry where activities may involve a risk to the safety of the employee. Real time data may be recorded so the employee’s activity can be viewed remotely in real time and vital statistics such as heart rate and body temperature can be monitored.^[57] As well as having valuable commercial use, smart clothing is becoming available to the personal consumer.

Snap Spectacles 3

An example of smart glasses is the Snap Spectacles 3 by Snapchat. These glasses have two cameras installed, capturing 3D photos and four built-in microphones that record audio.

Images are transferred to the user’s Snapchat account from where they can be exported or shared elsewhere.^[58]

North 2.0 smart glasses

These smart glasses released in 2020 present a new generation of connectivity for the user. The North 2.0 glasses include features such as access to Facebook, WhatsApp, SMS messaging, identifying places of interest, access to Amazon Alexa, Uber, weather reports, Google, Spotify and other applications.

Focals contains a companion app that can pair the glasses to the user’s smartphone. The app contains information such as home and work address, link to Amazon Alexa using voice control features, order an Uber ride, access to calendar, location and contacts. The user can also obtain a screenshot of what they are seeing through their glasses for pairing to the smartphone app.^[59]

Levi’s Commuter X Jacquard by Google Trucker Jacket

This jacket in collaboration between Levis and Google, allows the user to control music, screen phone calls or get directions via the user tapping or brushing the jacket cuff. ^[60] This jacket is connected to a mobile device via Bluetooth.

Sensoria fitness socks

Textile sensors are built into the sock.  A core microelectronics device snaps into a dock attached to each sock. Features include step counting, speed, calories, altitude and distance tracking, as well as cadence, and foot landing technique which generates an impact score.^[61]

The socks are connected to a mobile device via Bluetooth.

Tommy Hilfiger Xplore clothing range

This range of clothing includes hoodies, t-shirts, skirts and jeans. There is also a range of bags and a hat. Connectivity from the clothing to the paired mobile device is via Bluetooth.^[62]

The clothing is paired to the mobile device to collect, store and process user data such as when and how often the clothing is worn, GPS location and the times of day the clothing is worn. The advantage to the wearer is points are accumulated to redeem rewards from the designer such as gift certificates.^[63]

Ministry of Supply Intelligent Heated Jacket

This jacket is voice controlled through assistants such as Amazon Alexa. It uses machine learning to heat the clothing to the optimal level. Elements read include temperature, motion data, and user preferences to provide heat across the body.^[64]

Sensoria fitness range

 Sensoria provides a range of clothing including smart socks, bra, shirts, and t-shirts as well as a heart rate monitor. The devices can record heart rate, cadence, foot landing and impact forces, calories burnt, distance travelled, speed of travel and steps taken.^[65] The clothing pairs to the Sensoria fitness app on a user’s smartphone via Bluetooth.

The Sensoria Run v2.0 application records data generated by the wearer which can be displayed in a dashboard. This contains a map of the route travelled.

Partners may purchase the Sensoria development kit including textile sensors, electronics, software and cloud computing services for use in their product.^[66]

The data captured by smartwatches is similar to that available in the smartphone to which it is paired.

• • • Account user details.
    • Account registration details including email account.
    • Altimeter showing height above ground level (Useful in identifying location).
    • GPS details.
    • Links to third-party accounts.
    • Steps taken and speed of movement.
    • Temperature.

With all the smart technology being worn by individuals it opens the opportunity for the investigator to gain an accurate understanding of the activities of an individual at a specific scope of time of value to the investigation. For example, what were the smart devices recording in the time leading up to the death of an individual? This could be relevant whether it pertains to the deceased victim or the suspect. Whereas detectives would traditionally have to painstakingly gather data, and seek to corroborate it, the smart devices record very precise data that shows not only the activities of the persons wearing the smart devices but also their biometrics.

Suspects often provide versions of events that are self-serving, and witnesses’ memories may be inaccurate despite their best efforts to provide truthful and accurate testimony. Wearable technology has the potential to provide accurate and independent evidence as to events and the wearer’s participation in them.

When a person provides evidence in court, their evidence can be corroborated or disputed against the collected smart technology that provides the court with a higher standard of evidence to make a judgement.