The technology is emerging at an enormous rate and it is infiltrating every aspect of our lives. Solving crimes has become futuristic in its initial stage only. From trace evidence chemistry to retinal scanning, forensic technologies are so advanced at solving crimes that they seem like a scene of the science fiction thriller movie.
The area of forensic science draws from several scientific branches, including chemistry, biology, physics, biotech, computer science, with its focus on recognition, identification, and examination of evidence. Today, it has become a necessary part of the judicial system. Let’s find out some of the latest technologies that utilize a wide spectrum of sciences in order to obtain data relevant to crime and legal evidence.
16. Video Spectral Comparator 8000
VSC 8000 is used for examination of documents and comparison of inks. It is capable of viewing and recording the response of document evidence when exposed to light of different wavelengths. Reflectance, transmitted spectra, fluorescence and absorption are captured in real time. In order to obtain these results, combination of infrared luminescence, visible, ultraviolet, transmitted, coaxial or oblique lightning can be used.
The instrument makes it possible to complete these analyses, even after a piece of paper has been damaged by water or fire. It is also capable of reveling all levels of security features including anti-strokes inks, UV security threads, taggants, and latent images.
15. Automated Fingerprint Identification System (AFIS)
Before the 1970s, investigators analyzed inked fingerprints and several minutiae details like ridge dots, bifurcations, and the fingerprint cards filed according to patterns from the Henry classification system. It has now become more scientific with the use of portable scanners and computers. Forensic scientists, nowadays, can easily and quickly compare a fingerprint at a crime scene with an extensive virtual database.
Many states have their own automated fingerprint identification system that has capabilities like electronic image storage, latent searching and electronic exchange of fingerprints and responses. Fingerprint matching algorithms are categorized in terms of false positive and false negative error rates. They also vary in terms of features like image rotation invariance and independence from a reference point.
The accuracy of the algorithm, robustness to poor picture quality, and print matching speed are some critical components of system performance. Moreover, fingerprint matching has an exceptional computational burden. A few vendors deploy custom hardware while other use software to achieve matching speed and throughput.
14. Ear Print Analysis
When human ear is pressed against a specific surface, like helix, antihelix tragus, and antitragus, material present on the ear’s surface (skin oil, wax, etc.) are left behind, forming a 2D ear print. Each ear print contains a specific and individual anatomical marker that can be used to distinguish it from other discovered material, and compare it to other ear print on file in forensic databases in order to identify suspects. The height of an ear imprint can provide investigators identification and information regarding the stature of the perpetrator.
Forensic analysis of ear prints is more economical than DNA profiling, and it is thought to be more reliable in legal proceedings because it is virtually impossible to alter or tamper with. The first ear print identification of a criminal was made back in 1965 in Switzerland. Also, it has been successfully used to solve many criminal cases in the Netherlands and UK.
Criminals often hide illegitimate data on the XBox, thinking that a gaming console will not be seen as a likely evidence target, especially when conventional PCs are present in the same premises. XFT is a forensic toolkit developed by Collins to help investigators to access hidden files on the Xbox hard drive easily.
XFT mounts an image of the FATX file system (used in Xbox), allowing the investigator to explore the directory structure in detail. Unlike standard NTFS, and FAT32, there is little documentation on the proprietary FATX system. However, it is possible to create an image of a FATX hard disk and mount it on another device.
XFT can also record investigative sessions for playback in a court of law, providing more solid evidence for the prosecution.
12. Carbon-14 Dating
Carbon-14 dating (also called radiocarbon dating) has long used to estimate the age of certain objects. The traditional method is applied to organic remains up to 50,000 years old and exploits the fact that trace amounts of radioactive carbon are discovered in the environment.
Measuring Carbon-14 levels in human tissue helps forensic investigators determine age and years of death of unidentified human remains. Over the past 60 years, the amount of radiocarbon in human or their remains depends heavily on when they were born. To determine birth year, researchers focus on tooth enamel, whereas, to find death year, they use radiocarbon levels in soft tissues.
11. Age Progression and Image Modification
Age Progression is used in photographs to show what a person would look like at a specific age and it is most specifically used by law enforcement as a forensic tool in the case of missing person.
There are many internal factors considered before attempting an age progression drawing. Some of these factors include smoking, drugs, allergic reactions, genes, lack of rest, alcohol consumption, and diet over a certain period. On the other hand, external factors like weather, chapping skin, makeup, contact lenses, should be considered as well.
10. Luminol Spray
Luminol chemical exhibits chemiluminescene, with a blue glow, when mixed with an appropriate oxidizing agent. The glow only lasts about 30 seconds, but the examiner could document the effect with a long-exposure photograph. Since this spray reacts with the iron in hemoglobin, forensic analysts use it to detect trace amounts of blood at crime scenes.
With both Luminol and Fluorescein, the technique must be performed at nighttime or in a darkened room. Ambient light should not be strong as to overpower the fluorescent reaction during the photography and analysis.
9. Bloodstain Pattern Analysis (BPA)
As the name suggests, it is the pattern analysis that can examine the blood evidence left behind and obtain conclusions as to how the blood may have been shed. From the crime scene, forensic analysts can collect data from spatter patterns, voids and other marks which will help them recreating the sequence of events that occurred after bloodshed. BPA draws on the scientific disciplines of physics, chemistry, mathematics and biology.
The shape of the bloodstain pattern depends on the force used to propel the blood and also on the surface it lands. Impact spatter will create larger drops and be more concentrated in the areas directly adjacent to the action, while forward spatter from a gunshot wound will form smaller droplets over a wide range of area.
8. Audio and Video Forensics
The aim of audio forensics is to establish the authenticity of audio evidence, perform enhancement of recordings, interpret and document sonic evidence and reconstruct crime or timelines. Modern audio forensics technique makes extensive use of digital signal processing, adaptive filtering, discrete Fourier transforms, voice biometrics and electrical network frequency analysis.
Several enhancement techniques could be performed on video evidence too. However, if an analog copy or digital file has undergone additional compression during analysis process, the technique might not work at all. The enhancement of videos is done via sharpening, masking, video stabilization, interlacing and demultiplexing.
7. DNA Sequencer
Image credit: wikimedia
DNA is a precious key in the search for justice. It plays a significant role in several different situations, from the initiation of investigation through post conviction confirmation of the truth. We all are aware of that forensic scientists use DNA profiling to identify victims using trace evidence like hair, skin samples, whereas the more powerful DNA sequencer lets them to examine old bones or teeth to determine the particular ordering of individual’s DNA nucleobases.
Nuclear DNA found in blood, mucus, vaginal secretions, sperm, bone and hair roots can be in either liquid or dried form, and it is durable and long lasting. Restriction fragment length polymorphism (RFLP) is a traditional method of DNA analysis, which involves the comparison of lengths of specific DNA fragments.
The replication or amplification process is called polymerase chain reaction (PCR). It lets forensic scientists develop DNA profiles from extremely small samples. It’s a 3 step process – First, the DNA strand is denatured; the second step is Annealing, and lastly, DNA strand is heated again, activating a polymerase. The number of new DNA strands doubles every time the PCR process is performed, theoretically generating a billion copies after 30 cycles.
6. Alternative Light Photography: Forensic Nursing
The specialized role of forensic nurses goes far beyond medical care. They have advanced knowledge of the legal system and skills in injury identification, treatment and documentation. They often gather evidence, consults with legal authorities and provides medical testimony in court.
Although forensic nurses have many tools at their disposal to help victims of violence and abuse, Alternative Light Photography is one of the impressive tools to help see the damages that aren’t visible on the skin. A camera like Omnichrome uses orange filters and blue light to clearly display brushing below the skin’s surface.
The Omnichorme Helium-Cadmium laser is of coaxial geometry with integral hard glass-metal sealed resonator mirrors and utilizes Cadmium of natural isotopic abundance. The optimal choice of construction material, careful design of mechanical structure, Cadmium vapor and helium pressure control circuits defines the reliability and lifetime of the instrument.
5. 3d Forensic Facial Reconstruction
The advancement of 3d technology leads to a rapid, effective and cost efficient computerized 3d forensic facial reconstruction method, which has brought down the degree of error. Forensic facial reconstruction technique is a combination of both artistic skill and scientific methods. However, there are many different methods of manual facial reconstruction, the combination Manchester method is said to be more accurate for the positive recognition of a suspect or victim.
The 3d facial reconstruction software inputs a real life human remain and extrapolates a possible physical appearance. The aim is to create a picture from skull which provides a sufficient likeness of the an individual, which will further facilitate identification of skeletal remains.
4. Link Analysis for Forensic Accountants
Link analysis software is used to highlight some odd financial activities. It is generally used by forensic officers trying to trace illicit funds through a sea of paperwork. The software includes customer profiling, strange financial transactions and statistics to create probabilities of illegal activity.
The ratio analysis involves calculation of both traditional and nontraditional financial ratios like asset turnover, operating performance margin, working capital turnover, sales growth, asset quality and more. Since the ratios standardize organizations for size and other key factors, one would expect industry to follow similar trends.
3. Bite Mark Analysis and Comparison
Bite mark analysis and comparison involve standard techniques for analyzing and examining bite marks that are based on interpreting photographic evidence in which a bite is compared with the models of the teeth suspects. The angle and quality of the bite mark images and precision of the impression plays a key role throughout the investigation.
The technique is quite complex as the bite marks can be distorted by the anatomic location or the elastic properties of the skin tissue. The angle of the maxilla and pressure of bite can alter the appearance of a mark.
Most of the comparison techniques involve the fabrication of overlays. Several different methods to create overlays from a suspects’ definition includes hand tracing from wax impressions, dental study casts, xerographic images, radiopaque was impression and computer based method.
2. High Speed Ballistics Photography
Ballistics photography involves the utilization of 3d imagery (taken by high-speed cameras) for the forensic comparison of bullets. It helps you understand how bullet holes, gunshot wounds and glass shatters are made. Ballistics investigators often have to match a specific bullet or shell casing to a particular weapon, reconstruct crime scenes by estimating the distance between gun muzzle and the person who was shot, and determine the trajectory of the bullets fired.
The forensic technology has also designed a prototype Virtual Comparison Microscope (VCM). It utilizes images from BulletTrax-3d system and is especially helpful with deformed bullets, different types of rifling, and bullet fragments. Analyzing these in traditional microscope is quite time consuming as it constantly requires to re-adjust lighting, focus and perspective to get views from different angles. However, with VCM, bullets could be moved in any direction while maintaining a consistent appearance.
1. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA ICP MS)
When Shattered or broken glass is involved in a crime scene, putting all pieces together and reconstructing the design could produce some important clues like the force of impact, type of weapon, direction of bullet, etc. The classical method of forensic glass analysis is based on the physical properties like color, density, shape, surface, and optical properties have been relied on the comparison of control glass with unknown glass fragments.
However, LA ICP MS provides exceptionally low detection limits for elemental analysis and can be used to detect more than 70 isotopes. The highly sensitive instrument can perform quick, simultaneous, multi-element analysis. One of the big advantages of ICP MS is the number of sample types that may be accommodated. It has been adapted for solid, liquid and gaseous samples.
Modern ICP MS instruments cost over $300,000 and consume high purity argon, which costs up to $15,000 per year. Additionally, LA unit costs $125,000. This high price is the main reason behind the slow integration of ICP MS to routine casework.