Orchard House, Orchard Close, Severn Stoke, Worcester, UK WR8 9JJ
Telephone: 44 (0) 1905 371460 *** Fax: 44 (0) 1905 371477
E-Mail: sales@advanced-ndt.co.uk *** Website: www.advanced-ndt.co.uk
NEW TrAc Finder
An intensely powerful ALS lamp with a wide light beam and interchangeable filters. The TrAc Finder is made up of a crime kit plus a
portable UV lamp from the Labino “TrAc” series
NEW TrAc Finder Upgrading Kit
A kit intended for use by those already having a
Labino UV lamp
A range of accessories and add on's for special crime and forensic applications to compliment our high performance ultra violet UV Lights.
NEW Forensic Filters
Forensic filters: UV Crime Filter (wavelength 310-400 nm, peaks at 365 nm); General Crime Filter (wavelength 400-525 nm); Blue Crime Filter (wavelength 415-485 nm); Green Crime Filter (wavelength 485-530 nm). Filters sold mounted in filter frame for use together with
Labino UV lamp
NEW Forensic Goggles
Three different colours of forensic goggles -red, orange, and yellow - for use together with forensic filters and with the Labino TrAc Finder. Wrap around design fits comfortable over most prescription glasses. Weight: approx. 49 g. Material: polycarbonate. Meets ANSI Z87.1 impact standards. Protective case included.
A Guide To TrAc Finder
The TrAc Finder is a revolutionary alternative light source (ALS) that is designed to meet the needs of crime scene investigators and those performing forensic work. The TrAc Finder consists of a portable UV lamp from the Labino ® TrAc series, 4 interchangeable forensic filters and 3 forensic goggles, all neatly packed in a rugged durable case that is easy to carry.
Why do investigators use alternative light sources?
Many substances naturally fluoresce when illuminated with the right wavelength of light. Others absorb light and appear black when illuminated, such as blood. An effective ALS helps the forensic examiner detect potential traces of substances that otherwise might be impossible to see.
What sort of substances can be detected?
The purpose of the TrAc Finder is to assist the examiner in finding potential traces of various substances. This most often includes finding traces of biological fluids (such as semen, saliva, sweat, blood, etc.), narcotics, fibers, and fingerprints. Once the investigator has located potential traces, samples can be taken and sent to the laboratory for testing and analysis.
How do crime scene investigators use the TrAc Finder and filters during an investigation?
The TrAc Finder was designed to be easy to use. The filters can easily be snapped in place on the front of the lamp and are interchangeable. Knowing which filters to use and when, however is not an exact science. The investigator often acquires this knowledge through years of experience. This is because no two crime scenes are ever identical and the state and condition of material, substances and traces can vary.
Strengths and Benefits
It is the combination of strengths listed below that make the Labino TrAc Finder such a remarkable product.
Technical Data
Graph A
This graph illustrates what happens when a substance is illuminated with light of sufficient intensity and the right wavelength. Some of the energy is absorbed by the area that is illuminated but most of it is reflected. There is often so much reflection in fact that it can be difficult to see the fluorescence without using an additional barrier filter, such as goggles. The role of the goggles is to cut away the reflection so that the fluorescence can be seen.
Example 1: TrAc lamp
* with black UV filterIf you were to use a Labino lamp* with the UV Crime Filter, you would be able to see the fluorescence. This is because UV light is invisible to the human eye and therefore despite its intensity, you are not able to see the reflection. The UV Crime Filter also removes hazardous UVB radiation, making the lamp safer for the user.
Example 2: TrAc lamp
* with Blue Crime FilterIf you were to use a Labino lamp* together with a Blue Crime Filter for example, you would NOT see the fluorescent substance because you would be "blinded" by the blue reflection. Therefore you need either goggles or another sort of barrier filter. (The Labino Blue, Green and General Crime Filters remove 100% of the UV light transmitted from the lamp).
Ok, but what effect would goggles or another type of barrier filter have? The goggles filter away the blue reflection but let the fluorescent light pass through. The fluorescence has a higher wavelength and the goggles do not filter this away. This enables you to see the fluorescent trace.Example 3: TrAc lamp
* with no additional forensic filterIf you were to use a Labino UV lamp* without any additional filter (i.e. Black UV, Blue, Green, or General), you would NOT see the fluorescent substance because there would be so much white light that it would essentially "blind you". Your eyes would not be able to detect any fluorescent material, hence making the investigation next to impossible. Also note that the light contains UV light in such intensity that it could be a hazard for the user.
*Assumes that the Labino lamp is fitted with a Labino DUV35 light source.
Technical Questions
What happens when a substance is illuminated with light and why does a substance fluoresce?
When the molecules in the substance absorb the light, the electrons contained in the molecule become stimulated and start to move. The electrons move outwards from their circular sphere and then fall back to their original position. When these electrons fall back, they release energy. This "output" of energy is lower than the initial "input" of energy from the light source. The lower energy has a longer wavelength that in this case falls into the visible range of light. It is this longer wavelength of energy that is visible to the human eye and this is called fluorescence.
What is the range of wavelengths that a TrAc Finder lamp emits?
A Labino lamp fitted with the DUV35 bulb (UV light source) with the clear glass protection filter, emits light between 300 and 700 nanometers.
What is the purpose of using forensic filters?
Essentially, when you choose a forensic filter, you are choosing which wavelength you are going to use, and this of course influences which substances you can see. Depending on what you are looking for, you add a filter that
cuts away the unwanted wavelengths . That is because you don’t want to see all possible substances, such as detergents for example, or cleaning agents, and so forth. If for example you place a Blue Crime Filter on the front of a Labino lamp*, then you would only see substances that fluoresce under those wavelengths that the blue filter permits (415-485 nm).*Assumes that the Labino lamp is fitted with a Labino DUV35 light source.
Forensic Filters
Forensic Filters
UV Crime Filter …………wavelength 310-400 nm (peaks at 365 nm)
General Crime Filter……. wavelength 400-525 nm
Blue Crime Filter………... wavelength 415-485 nm
Green Crime Filter………wavelength 485-530 nm
UV Crime Filter (310-400 nm)
Cuts away wavelengths outside of 310-400 nanometer range.
Can be used when searching for traces of blood. Blood does not fluoresce but rather absorbs UV light and appears black. Effective on dark fabric and other soft materials. Can also be used to find fibers.
Some body fluids, such as saliva, urine, and semen may fluoresce and appear a light yellow color when illuminated with UV light and when using the UV Crime Filter. Some narcotics may also fluoresce when using this filter.
In some cases, yellow goggles improve the contrast.
General Crime Filter (400-525 nm)
Cuts away wavelengths outside of the 400-525 nanometer range.
Often used to get a quick overall view of the crime scene and to locate potential traces of substances.
Mostly used together with orange or red goggles.
Blue Crime Filter (415-485 nm)
Cuts away wavelengths outside of the 415-485 nanometer range.
Often used in combination with fluorescent dye like Basic Yellow 40, or Ardrocks and ultraviolet light after cyanoacrylate development of latent fingerprints.
Best used together with yellow goggles or can be used with orange goggles, depending on light conditions, material and state of substance.
Green Crime Filter (485-530 nm)
Cuts away wavelengths outside of the 485-530 nanometer range.
Works well for biological substances especially if the background is fluorescent and if the Blue Crime Filter isn’t sufficient to show traces.
Mostly used with orange or red goggles.
This filter is optimal when using DFO* method for developing fingerprints.
Forensic Goggles
Forensic Goggles
Yellow goggles transmit 2% at 480 nm
Orange goggles transmit 2% at 549 nm
Red goggles transmit 2% at 583 nm
Labino colored forensic goggles are intended for use together with Labino forensic filters. Some substances and traces are more visible to the human eye when seen through forensic goggles. The effect of combining certain forensic goggles with certain forensic filters depends often on the light conditions, surface that the evidence is on, and the state of the substance or trace. It is therefore not possible to say exactly which glasses should be combined with which filters since each crime scene is unique in nature.
Yellow goggles
Generally used with Blue Crime Filter and UV Crime Filter to improve contrast.
Transmits 2% at 480 nm.
Orange goggles
Generally used in combination with Green Crime Filter to detect body fluids.
Transmits 2% at 549 nm.
Red goggles
Generally used in combination with General Crime Filter to improve contrast.
Transmits 2% at 583 nm.
Terminology
Below is a general list of terms commonly used when discussing forensic lamps and forensic science.
Excitation wavelength:
Light emitted from the light source (ALS) that creates fluorescence – this is the excitation wavelength. The wavelength needed varies depending on the characteristics of the substance. This is the wavelength that is absorbed by the sample and which makes the electrons excited.Fluorescence:
Fluorescence occurs when light of a visible color is emitted from a substance under stimulation or excitation by light. Fluorescence can be induced in certain substances by stimulation with light (energy) of a correct wavelength. The energy (light) that is absorbed by a substance is emitted back with a lower energy due to loss of energy in the molecules. Stokes law states that the wavelength of the fluorescent light is always longer than that of the exciting radiation. This is the "Stokes shift". The light that is emitted is called fluorescence.Barrier filter: For example goggles or camera filter. What a barrier filter is doing is filtering away the reflected light from the excitation light and makes the fluorescence visible. Otherwise the viewer can be "blinded" by the reflection.
Absorption filter: Absorption filters are commonly manufactured from dyed glass or pigmented gelatin resins. Absorption filters pass certain wavelengths of light while blocking or absorbing others.
Interference filter: An interference filter reflects one or more spectral bands or lines and transmits others. It is more of an "energy filter". It blocks various wavelengths. The effect of this is a more distinct cut-on and cut-off of the transmitted wavelengths. The Labino Blue, Green and General filter use this technique. This means higher transmission over the whole wavelength span.
MPXL: MPXL lamp stands for Micro Power Xenon Light. This technology combined with our specially designed electronics and light bulbs (both UV and white) enables Labino to produce lamps that are among the most powerful on the market.
Clear glass protection filter: The primary purpose of the Clear Protection Filter is to filter away the dangerous UVC and UVB wavelengths that exist below the UVA range. Visible and UVA light passes through the Clear Protection Filter. It also enables the Labino lamp to be classified as IP65 certified since lamps fitted with this filter are both water and dust resistant (when installed with an o-ring).
Commonly used chemicals in forensic science:
DFO: 1,8-Diazafluoren-9-One, or DFO as it is more commonly called, is a ninhydrin analogue and amino acid reagent which produces fluorescent fingerprints.
Basic Yellow: Basic Yellow 40 is a highly fluorescent dye stain which stains cyanoacrylate-developed latent prints. When illuminated with an ultraviolet lamp or Forensic Light Source, latent prints fluoresce brightly, and weakly-developed latent prints that could not be seen under normal viewing conditions may be easily seen and photographed.
Cyanoacrylate:
Cyanoacrylate is the generic name for ethyl-2-cyanoacrylate, and 2-octyl cyanoacrylate or n-butyl-cyanoacrylate, which in essence is an
adhesive
(similar to "glue")
. One non-adhesive use for cyanoacrylate is as a forensic tool. Fumes from warmed CA can develop latent fingerprints on smooth surfaces like glass, plastic, etc. The invisible fingerprint residues react with the CA fumes and atmospheric moisture to form a white polymer (polycyanoacrylate) on the fingerprint ridges and can then be recorded.
The developed fingerprints are, on most surfaces (except on white plastic or similar), visible to the naked eye. Non-visible or poorly visible prints can be furthermore enhanced by applying a luminescent or nonluminescent stain, such as Basic Yellow (see above).
Crime Applications for UV
UV & Blood
DETECTING BLOOD STAINS
There are several common ways to detect blood at the crime scene. One very easy and quick way to detect blood is to use UV light.
When to use UV light to detect blood:
•
Reduce the risk of collecting unnecessary stains• Detect blood on dark, red or violet surfaces
• Find blood stains that are concealed by paint
Reduce the risk of collecting unnecessary stains
By using ultraviolet light it is possible to do an effective and quick check for possible bloodstains. A bloodstain exposed to UV light absorbs all light of that bandwidth and does not reflect back – that is to say, it does not fluoresce in any way. Thus the stain will appear black under UV. Although not a conclusive test for blood, it is an effective presumptive test and can often eliminate the unnecessary collection of stains that appear to be blood are actually from another source.
Dark surfaces
The UV light source is also effective for providing sufficient contrast of bloodstains that are found on red- or violet-colored objects. Such stains often fade into the background so well that it is impossible to photograph them. Ultraviolet light often provides sufficient contrast between the background and stain to allow the stains to be visualized in a photograph.
Blood concealed by paint
It is not uncommon that a perpetrator of a crime tries to get rid of potentially incriminating evidence. This may include painting over areas that have been exposed to blood. To the naked human eye it is next to impossible to see that a blood stain has been painted over. By using ultraviolet light however, it is possible to detect blood stains that have been concealed by paint.
Under normal light, these stains are difficult to see and nearly impossible to photograph. A UV light source causes the stains to absorb all light and appear black, while the background cloth lightens and reflects the light.
UV & Body Fluids
SEMEN | URINE | SWEAT | SALIVA
Detecting body fluids at the crime scene is a delegate task. Using a UV light lamp however makes the job easier.
When to use UV light to detect body fluids:
Mark up the crime scene
Most stains from body fluids can be seen when using a high intensity UV light. That is to say that most body fluids have some fluorescent nature or reveal themselves in a special way when illuminated with UV light. In most cases it is not possible to see such stains otherwise. The most effective way of using the UV lamp is to use it to ‘mark’ the crime scene. In other words, you mark all stains that could be useful ‘traces’. When using an intense UV light it is also possible to see things at a distance that otherwise would be nearly impossible to see. While the UV light cannot confirm exactly what sort of stain you are looking at, it does indicate where the stains or body fluids are. This makes it possible to then take samples or perform further investigation.
Dark textiles
The high intensity UV light is a superb complement to more advanced Alternative Light Sources due to the fact that ALS’s often have limitations in finding body fluids on very dark textiles. High intensity UV light is being used for example to examine the interior of black coloured ‘robber’ masks, and to illuminate the sweat seen on the inside of these.
What body fluids are fluorescent by nature?
•
Semen (DNA)
•
Vaginal secretion (DNA)
•
Urine (DNA if it contains blood or other body fluid)
•
Sweat (DNA)
•
Saliva (DNA)
Semen
Semen is very fluorescent by nature and the fluorescence can be observed on dark as well as light textiles when illuminated with an intense UV light, without the need for using coloured goggles.
Vaginal secretion
Vaginal fluid is very hard to detect at all times, as it has a very weak fluorescence.
Semen
Urine
Saliva
UV & Finger Prints
COLLECTING FINGERPRINTS
There are several methods of gathering fingerprints, and fluorescent powder is used for some of them. Such powder is used in combination with ultraviolet light and can be used on both nonporous smooth and rough surfaces.
Nonporous smooth surfaces:
•
Painted or varnished surfaces
•
Glass or Plexiglas
•
Most plastics
Nonporous rough surfaces:
•
Vinyl
•
Leather
•
Textured countertops
•
Textured surfaces
Use fluorescent powder and UV light when:
•
The surface is dark, patterned or spackled
•
The fingerprint is very weak
•
The surface is not to be damaged by carbon
•
The possible DNA on the stain is not to be damaged by carbon or other powders
Dark, patterned or spackled surfaces
Putting dark powder on a dark patterned or speckled surface makes it very hard to see the fingerprint. By developing the print with fluorescent powder and a brush, and illuminating it with UV, the fingerprint glows and is easy to photograph. This method is very successful on beer cans for example.
Weak fingerprints
Fluorescent powder is very ‘delicate’ compared to common powders used for fingerprints. It is therefore very useful when trying to detect weak prints. If you develop the print with a very small amount of fluorescent powder (and brush) and lluminate it with a UV light, the fingerprint will glow and become therefore easy to photograph.
Avoid damaging surface with carbon
If you are going to develop a fingerprint on a surface that you do not want to damage with carbon – i.e. a computer made of light plastic – fluorescent powder is highly recommended. Use fluorescent powder and a brush, and illuminate the print with UV. You need only use a very small amount of fluorescent powder to achieve results, which makes it useful on areas you can’t clean, like the inside of a computer for example.
Avoid damaging fingerprints with carbon
UV & Fire Investigation
How is UV light used in arson investigations?
UV light is used to:
•
Identify the presence of accelerants
•
Identify pour patterns
Accelerants
UV light not only assists in identifying the presence of accelerants (
a substance that accelerates the spread of fire or makes a fire more intense
)
, but also in rapidly locating accelerant residues, and assisting in locating the point of origin of the fire. The color which accelerants glow is affected by heat exposure. The longer an accelerant is exposed to heat (i.e. the origin), the more differentiated its fluorescence color will be from other less exposed areas. Evidence of accelerants gets absorbed in a fire and is therefore almost always invisible to the naked eye. The area tarnished by accelerants however is easily discernible under UV light.
Hydrocarbons
Volatile hydrocarbons such as gasoline, kerosene and other petroleum fractions such as benzene, acetone, grease, lard, vegetable oils, paints, etc fluoresce when exposed to UV light. By using UV light, investigators can accurately identify locations where samples should be collected for further laboratory analysis. UV light can also be helpful in locating fragments of incendiary devices since explosive wrappings are frequently fluorescent. Samples collected in cans and plastic evidence bags can be heated in warm water to form condensation. The latent accelerant residue rises to the surface and this can be seen under UV light.
Pour patterns
UV light has been used to identify pour patterns, the shape of an accelerant container and pour trails leading back to containers. UV light will indicate accelerant long after its odor is discernable. Masking an accelerant will not prevent its UV detection. Accelerant on skin or clothing will fluoresce as well.
Advantages of UV light compared to canine or mechanical ‘sniffers’
• The ‘sniffer’ indicates a general area of saturation yet does not detect specific infected areas. This makes pour pattern sampling difficult. UV light detects specific areas.
• The ‘sniffer’ is effective only two to three days after saturation. UV lamps have been proven to effectively fluoresce samples up to two months after an incident.
• After a lengthy hot fire, the odors of accelerants have usually disappeared.
ENVIRONMENTAL INVESTIGATIONS
Illegal dumping
UV light can assist in environmental investigations by indicating the presence of hydrocarbons on land and in water. Illegal dumping has been traced using this technique. Trace dyes can be used along with UV light, and some radioactive substances fluoresce as well.
PROPERY MARKING AS A CRIME COUNTERMEASURE
INTERCEPTION OF SECRET MESSAGES
Successful use of invisible ink depends on not arousing suspicion. Telltale signs of invisible ink, such as scratches from a sharp pen, roughness or changed reflectivity of the paper can be obvious to a careful observer who simply makes use of strong light, a magnifying glass and their nose. Also, key words in the visible letter, such as 'red cabbage' or 'heat', in an odd context may alert a censor to the use of invisible ink. By using ultraviolet light, messages can be quickly screened for invisible ink and also read without first permanently developing the invisible ink. Thus, if a censor uses this method to intercept messages, he may then let the letter be sent to the intended recipient who will be unaware that the secret message has already been intercepted by a third party. A "screening station" could theoretically involve visual and olfactory inspection, an examination under ultraviolet light and then the heating of all objects in an oven before finally trying exposure to iodine fumes.
UV & Invisible Ink
COCAINE | AMPHETAMINE | ECSTACY
Fluorescent narcotics
•
Cocaine
•
Amphetamine
•
MDMA tablets (including some but not all Ecstasy tablets)
Cocaine
Cocaine having a purity of at least 87 % fluoresces clearly when illuminated with UV light.
Amphetamine
Some amphetamine having a purity of 78 % (i.e. of Dutch, Baltic or Polish origin) are clearly fluorescent when illuminated with UV light. Even small amounts of amphetamine are easy detectable because of their fluorescent nature.
MDMA tablets
Some MDMA tablets (i.e. Ecstasy with four-leaf clover logotypes) are clearly fluorescent with UV. Even small fragments are easily visible as they fluoresce intensively.
UV & Narcotics
WHAT MAKES THE LABINO
UV LIGHT UNBEATABLE?
•
Its high UV intensity creates new possibilities in the field of crime investigation.
•
Labino
high intensity UV lamps are so powerful that they can even be used in normal lit areas or outdoors while still maintaining a high contrast-to-background while maximizing the probability of detecting valuable traces.
•
Immediate start and restart – full power in approximately 5-15 seconds.
•
Dust tight and temporary water proof, IP65 certified.
