CAPTR

spatial crime scene documentation

Crime scene investigators use a variety of tools to capture and document crime scenes and potential evidence. These tools include cameras, measuring devices, powders, different light sources and casting materials. Creating a rich collection of documentation material is crucial for reconstructing the course of events and presenting relevant information in court.

CAPTR is a spatial crime scene documentation system that provides professional crime scene investigators with a powerful tool that helps them to effectively document crime scenes using photos, videos, audio recordings and 3D-scans. The system consists of a wearable computing unit and a handheld scanning device. By embedding multiple layers of captured information in a 3D representation of the crime scene, professionals can digitally revisit the scene afterwards and create rich court presentations of the investigation results. 

Term Project - Solo
Umeå Institute of Design
Duration: 10 weeks
2023

In collaboration with:

01

PROCESS

Research

The research consisted of three major parts:

• In our first field trip we visited the Police Education Unit at Umeå University where we learned about the basics of forensic investigations.

• For the second field trip we visited the Police station Umeå where we had the chance to talk to two professional forensic technicians.

• After structuring all gathered information, we conducted further desktop research in groups and deepened our knowledge.

Pain Points

• Tedious documentation of the crime scene with various measuring instruments, scribbles and photos.

• Extensive work on recreating the crime scene from captured data for the report.

• Time-consuming documentation of single traces using various tools.

Design Opportunity

• Reduce time spent to document the overall crime scene and individual evidence objects.

• Reduce the time spent to recreate the scene when writing the report.

• Enable Crime Scene Investigators to create rich and significant presentation material for court.

Concept

The project scope was to design a professional 3D-scanning and documenting device that is tailored for the use in crime scene investigations. I aimed for considering the whole process of using the product, including the steps after leaving the crime scene.

Main features:

• fully wearable solution

• convenient photo/video/audio documentation

• quick 3D-scanning of crime scene

• real-time feedback on scanning

• detailed 3D-scanning of evidence objects

• ergonomically adapted for longer investigations

Workflow Testing

To get a better understanding of the process of using a 3D-scanning system in an investigation, I staged a crime scene outdoors. Then I reenacted securing and documenting the crime scene using the rough mock-up I built earlier. This provided me with valuable insights and helped to further define the features of the product.

Concept Validation

I had the chance to show my concepts to both an active Swedish forensic technician and a Swedish 3D-scanning specialist who works on the development of visualisation methods for the Swedish Police. Both approved the concept and the technical thoughts I had on the product. Furthermore, they gave me valuable insights into current developments in their field of profession.

Design Refinements

In consideration of the received feedback from tutors, the forensic technician and the 3D-scanning specialist, I continued developing the design. I went through multiple iterations on all important components of the system.

CAD

Based on the final ideation sketches and 3D-scans of the mock-ups, the backpack and the handheld device were modeled using Rhino 3D.

02

FINAL DESIGN

CAPTR

CAPTR is a spatial crime scene documentation system that provides professional crime scene investigators with a powerful tool that helps them to effectively document crime scenes using photos, videos, audio recordings and 3D-scans. The device consists of a wearable computing unit and a handheld scanning device. While the handheld device is made to document traces in detail, a combined LiDAR and camera system worn on the shoulders can be used to capture the surroundings automatically. All gathered information is then embedded in a digital 3D version of the crime scene and can be easily accessed. This allows the investigators to revisit the scene in 3D and create meaningful court presentations of the investigation results.

Backpack - Structure

The backpack consists of a hard shell and a soft, flexible frame, which protects the components within the hard shell and makes the backpack more flexible and comfortable to wear. The hard shell contains all computing components, digital storage and the battery. The battery - which powers all components - is removable for charging. Integrated antennas help transmitting captured data to the cloud for backups and and further processing. Inbetween the hard shell bottom and the soft frame, there is an outlet for the power and data transmission cable that leads to the handheld part of the system.

Backpack - Features

Pressing the power button on the top part starts up the backpack. After picking up the backpack, a stiff bracket equipped with 3D-scanning sensors can be pulled up so that the sensors sit right on top of the forensic technicians shoulders. This way, the sensors have a 360° field of view and can therefore capture the whole environment. The process of the automatic scene scanning can be initialized by the operator using the interface of the handheld device. The shoulder part connects the sensors of the left and right side in a rigid way, which reduces processing effort. Connected through elastic straps, that contain extendable wires, the sensors on the shoulder part receive power and can send captured data directly to the processing unit.

Handheld Device

The process of getting the handheld device ready for documentation is quick and simple.

Turn on device

Remove lid and flap out arms

Handheld Device - Features

The handheld device houses a system for near-infrared structured light scanning, which is a 3D-scanning technology suitable for creating detailed scans of objects under various light conditions. This includes a projector for generating infrared light patterns and three infrared sensitive cameras that capture the patterns projected on the subject. The main camera is also used for taking conventional photos and videos. Two powerful LEDs provide light in dark environments. Recessed lens cap magnets hold a lens protection cap that can be put on when not using the product.

Controls

Manual controls help to use the most important functions of the device in a quick and reliable way. Optionally, the device can be operated via the touchscreen.

Interface

The interface always shows the current recording mode (photo/video/3D-scan) at the bottom of the screen. To make the operation more reliable and to avoid mistakes, the interface provides the user with information about ongoing processes.

Holster

An important feature of the hand unit is a holster that allows the user to quickly attack the device to the belt strap, which is part of the backpack. This allows the operator to have both hands free for navigating on the scene while the device can hang safely on the dedicated holster. When pressing the device against the pill-shaped holster pin in a horizontal position, the pill-shaped, spring-loaded plate is pushed in. Then, the device can be rotated down into a vertical, hanging position, locking the pin in its handle.

Final Physical Model

Eventually I built a physical design model of the handheld unit to make the design tangible and allow for good judgement of ergonomics and proportions.