Evidence Examination: Anytime, Anywhere
Written by Mitchell M. Rohde, PhD and Jennifer Chang   


Forensic laboratories face a constant challenge in balancing the needs of their client base with efficient operation. The demand for evidentiary examinations has increased tremendously over recent years, with media-fueled interest from juries, as well as cases that span county, state, national, and international borders.

The area of bullet and cartridge case examination is no exception to this growth pattern. Increasingly, laboratories are strained by a rising demand for examinations, while the pool of experienced expert examiners is often limited. The situation is critical, since each examination requires two expert examiners: one to perform the original analysis and another to independently verify the analysis (“seconding”). A long-term solution to this problem will require a substantial number of new examiners to be trained and integrated. In the short-term, however, laboratories need technical solutions that enhance the utilization of existing examiners.

Currently, an examiner must typically be physically co-located in a laboratory with the evidence and a comparison microscope. If the evidence is collected far from the lab, law enforcement must either (a) ship the evidence to the lab, potentially introducing questions regarding the chain of evidence, or (b) transport the examiner to a lab near the evidence-collection site. The latter is preferable from an evidentiary perspective, but is extremely inefficient: examiners can spend days traveling to perform a single comparison that may take hours or even minutes. Examiners at the U.S. Army Criminal Investigation Laboratory (USACIL) have traveled from Georgia to Afghanistan to perform comparisons. Domestic cases are similar, with Michigan State Police (MSP) examiners routinely spending up to 12 hours traveling between labs located throughout the state to perform a single comparison. Whether it be for domestic or international examinations, establishing the physical co-location of evidence and examiner—or rather, two examiners—is often difficult, expensive, and inefficient.

To address this growing problem, the Technical Support Working Group (a division of the Department of Defense) teamed up with USACIL, MSP, and Quantum Signal, LLC to develop the Teleforensic Examiner for Firearms, an innovative system for remotely examining bullets and other evidence. This “teleforensics” capability allows examiners to perform all functions necessary to conduct an analysis, including mechanically positioning the bullet (or other evidence), adjusting lighting, controlling microscope parameters, and capturing diagnostic-quality images for evidentiary reporting. Designed as an add-on to existing comparison microscopes, the system forms an IP-based network of examination stations that can be accessed remotely over communication links from anywhere in the world.

Quantum Signal Teleforensic Examiner System TSWG ballistics comparison microscope Quantum Signal Teleforensic Examiner System TSWG diagnostic image ballistics comparison microscope
These two images illustrate the concept of the remote ballistics microscope application. The technician in the left image has mounted evidence in a comparison microscope. In the right image, the expert examiner connects remotely—via an IP-based communications network, LAN/WAN modem, or satellite—and performs examinations.

The authors developed the Teleforensic Examiner for Firearms as a teleoperated comparison microscope that enables an off-site examiner to study markings on bullets and spent cartridge cases for matching purposes. Remote investigators can manipulate and examine materials placed in a motorized mount (by an onsite technician) under a comparison microscope. All aspects of the microscope that are typically controllable (such as zoom, focus, and lighting) are controlled via a user-friendly teleoperated interface and a Windows-PC based application. This system enables a single ballistics expert to efficiently analyze evidence located at a host of different locations, directly from his or her desktop. Alternatively, multiple forensics experts can connect to a single microscope and collaboratively contribute suggestions or perform analysis. The system also enables examiners to simultaneously observe multiple pieces of evidence on separate mounts at different locations, emulating the traditional comparison microscope by a local operator.

Software Capabilities

Quantum Signal Teleforensic Examiner System TSWG comparison microscope bullet mount
This is a rendering of the stage platform with detail of the bullet mount. The dotted lines illustrate teh direction of motorized movement.

Quantum Signal Teleforensic Examiner System TSWG technician station user interface diagnostic image ballistics comparison microscope
Technician Station User Interface

Quantum Signal Teleforensic Examiner System TSWG diagnostic image ballistics comparison microscope
Diagnostic image. Annotations, shapes, and arrows can be added to highlight particular features.

The Teleforensic Examiner System consists of a Remote Examiner Station and one or more Technician Stations that are connected via an IP-based network. The Remote Examiner Station is custom, PC-based software that allows an off-site examiner to view and manipulate samples mounted under a Leica FS C microscope located at the Technician Station in the forensic laboratory. The remote examiner can communicate with the technicians manning the Technician Station utilizing voice (VOIP) and text chat (IM). They can exchange files and other information throughout a session. The results of the examiner’s work can be saved for later review along with a log consisting of notes and performed operations.

The system supports a network of Remote Examiner Stations and Technician Stations via secured or unsecured communication networks. An examiner can connect to a single Technician Station and examine evidence, or to multiple Technician Stations simultaneously to compare a single piece of evidence from each Technician Station. This configuration allows examiners to compare recovered shells and cases to reference the evidence very quickly without shipping to a single location (and thus creating chain-of-evidence concerns). This capability has never existed in the forensics community, and it is a major feature of the system.

To ensure proper functionality when bandwidth is limited, the Teleforensic Examiner System varies the frame rate, resolution, and quality of the video image. This allows the user to easily balance real-time control of the microscope with diagnostic-quality image viewing. When motion is detected in the video image, quality and resolution are reduced in favor of a high frame rate, to enable precise control. When the positioning mechanisms are idle, the resolution and quality are automatically increased, and the frame rate is decreased, to allow for higher image fidelity within the available bandwidth. This adaptive compression enables operation even over very low-bandwidth connections.

Data transmitted between the Remote Examiner Station and the Technician Station is sensitive by nature because it often involves pending criminal investigations and legal proceedings. Therefore, it is crucial to ensure that the data is protected and only legitimate stations can connect to other stations. To allow connections only between legitimate stations, each Remote Examiner Station and Technician Station has its own identity certificate that identifies the station name, serial number, and other associated information. Whenever one station requests a connection to another station, the receiving station checks the certificate of the requester to confirm that it is legitimate. If the certificate is not recognized, the receiving station prompts the user to review the certificate and approve or reject the connection. In addition, all communications over the Teleforensic Comparison Microscope connection are encrypted.

Hardware Capabilities

For the Teleforensic Examiner System to be truly effective, the off-site examiner must be able to manipulate the evidence as easily as an on-site examiner. The Leica FS C has a motorized stage that moves along the x-, y-, and z-axes, but the standard Leica bullet mount requires a technician to manually change the angle, tilt, and rotation of the bullet. The standard Leica lighting also requires manual adjustment. To create a fully teleoperated system, the authors designed and custom-built a stage platform consisting of a motorized bullet mount and light panel. The remote examiner can control the x-, y-, and z-axis movement of the Leica stage, the height, tilt, angle, and rotation of the bullet, and the height, angle, and intensity of the light panel. This capability gives off-site examiners the full range of positioning control that an on-site examiner would have, and results in a capability that did not previously exist in forensic science.

Diagnostic Images, File Transfers, and Log Files

Another key component of the Tele-forensic Examiner is the capability to capture high-resolution, diagnostic-quality images that can be used for reporting purposes or courtroom proceedings. The examiner or technician can annotate a diagnostic image by writing notes or drawing shapes to highlight specific features. If the examiner is viewing two stages (from either one or two microscopes), both stages are captured in a single image. Diagnostic images can be transferred from the Technician Station to the Remote Examiner Station. The system also supports transfer of other files during the session. This allows additional case-related information to be exchanged, such as crime scene photos or scanned documents.

For each session, a transcript is created that automatically logs events as they occur. Diagnostic images, chat transcripts, or other files may be attached or referenced within the log. Log files are maintained at both the Remote Examiner Station and the Technician Station. All log files are automatically synchronized as events occur.

Going Forward

Early prototype systems have been delivered to USACIL and MSP, and are currently undergoing refinement. For USACIL and other federal agencies, the growing need for examinations in forward theaters is generating new mobile and permanent forensics laboratories in those locations. While having a technician and equipment may be possible in these labs, it is unlikely that two or more expert examiners will be constantly available on-site; thus, teleforensic reach-back capabilities are critical if the labs are to meet their mission. Couple this with the geographically disparate nature of forensic labs located throughout the United States, and it is clear that the need for teleoperated microscope systems is substantial.

It should be noted that the Teleforensic Examiner for Firearms system and technology are not restricted to bullet and cartridge examination—it can be applied across other forensic disciplines. Clothing, hair, skin, bones, and other biological forensic material can be examined with the Teleforensic Examiner, and the authors are expanding the technology based on user input and needs. The utility of this tool is broad for laboratories seeking to improve their efficiency and fiscal performance.

For More Information

To learn more about the Teleforensic Examiner System, please contact Jeff Huber at TSWG or Dr. Mitchell Rohde at Quantum Signal.

About the Authors

Dr. Mitchell Rohde is the CEO and co-founder of Quantum Signal, LLC, an advanced engineering research and development firm located in Saline, Michigan. He holds an MS-EE, MS-BME, and PhD-BME from the University of Michigan in Ann Arbor.

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a Project Analyst at Quantum Signal, LLC, and has been involved in a number of forensic-related technology development projects at the company. She holds a BS-IOE from the University of Michigan in Ann Arbor.

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Item of Interest

The language barrier between English-speaking investigators and Spanish-speaking witnesses is a growing problem. (Updated 28 February 2011)