Radiography Uncovers More Than Meets the Eye
November 2, 2006
The field of criminology booms like never before due to increased public awareness through network and cable television programs and miniaturization of computers and electronics. This has led to an increase in the number of local criminal laboratories which in turn has contributed to the rise in the number of imaging procedures performed each year. Advancements in imaging technology have led to the design of smaller imaging systems used specifically for criminal investigations. In addition to being compact and versatile, they produce conclusive information and these units are affordable, safe to use, easy to install, and simple to operate.
The use of radiographs as a means of identification for human remains is a well-established method as performed by criminologists, crime investigators, and the forensic science community. Other applications for radiography in investigations include:
Hidden Objects: X-ray is commonly used to view the inside of a package or object to locate and identify elements hidden to the eye. Contraband, drugs, explosives, weapons, and potential bombs are readily detected using radiography.
Firearms: X-ray can determine whether a weapon is loaded or "booby-trapped.” If a weapon is rusty or corroded, a radiograph gives valuable information as to overall firing condition before the weapon is disassembled. Radiographs of two similar weapons have been valuable in court to illustrate differences in inner mechanical structures.
Ballistics: Radiographs showing the area surrounding a bullet hole provide useful information on the type of bullet, firing distance, and direction of fire. X-ray separates the background material (cloth or skin) from the lead and powder particles and displays the “splatter pattern” caused by the discharge of the weapon. By varying the exposure of the X-ray beam, powder residue, unspent powder, or lead fouling can be viewed selectively.
Fingerprints: Special techniques using X-ray can uncover latent fingerprints from difficult surfaces such as plastic, biological material, and colored or printed paper.
Documents: X-rays can reveal surface details in paper as well as indentations, obliterations, alterations, and watermarks.
Serial Numbers: Concealed or altered serial numbers may be visualized in radiographs as well as identifying markings hidden inside the seams of clothing.
Equipment manufacturers know that preserving evidence and the ability to quickly produce conclusive results are central to the design of investigative equipment. Today's labs have vast array of analytical X-ray equipment from which to choose and their costs range from $10K to $300K. At the top end of the equipment spectrum are systems designed for Microspectophotometry, Scanning Electron Microscopes (SEM), Energy-Dispersive Spectroscopy (EDS), and X-ray Fluorescence (XRF) all of which are cost prohibitive for most labs. Basic X-ray of the skull region, small body parts, and portable evidence often does not require such sophisticated equipment and a simple radiographic system priced under $20K is effective for these examinations.
Airport security type systems or modified human systems were formerly used, but today's compact radiographic systems are designed for criminology purposes and provide numerous benefits to the laboratories that use them. These freestanding units operate from 115 VAC and are completely self-contained eliminating the need for special lead barriers. Most notably, dedicated systems incorporate the use of a micro-focus X-ray tube and often provide magnification capability to maximize image resolution.
Automatic Exposure Control (AEC) is a useful tool offered as an option on some systems. AEC helps to control image quality by eliminating the guesswork of setting techniques manually. Radiation is transmitted through the object and converted into an electronic signal using a photo-timing device. The exposure is terminated when a predetermined level of radiation is reached.
Digital radiography is also becoming more popular in laboratories because it provides instant images and replaces the need for X-ray film and processing. In digital imaging, a scintillator is typically used which converts incoming X-ray photons to light and a photo detector converts light into an electronic signal. Digital images are viewed and stored on an image-processor and images are transmittable over the Internet.
“The world is full of obvious things which nobody by any chance ever observes.” Sherlock Holmes-The Hound of the Baskervilles
The scientific and technology tools now available to criminologists and pathologists combined with the speed and accuracy needed in criminal investigations has had a dramatic and profound impact on the field of forensics. Like never before, multiple modalities are used to evaluate and document forensic studies. These findings are widely accepted and powerful in criminal court convictions. Radiography has proven its usefulness time and again, and its affordability makes it accessible to any lab, regardless of its size.
Bryan Goode is President and CEO of Faxitron X-Ray Corporation, located in Wheeling, IL; 847-465-9729;Web Site
