Using the FIVIS smoker from the American company 3M to detect traces of hands.

Using the FIVIS smoker from the American company 3M to detect handprints.

USING THE FIVIS SMOKER FROM THE AMERICAN COMPANY 3M TO DETECT HANDPRINTS

As already noted, cyanoacrylates, in other words, superglue, have been used for many years in foreign forensic practice to detect fingerprints.

Since the 1980s, this method has been successfully used in laboratory conditions by experienced specialists for uniform fumigation of material evidence in special closed containers using catalytic or thermal acceleration of the process. The use of cyanoacrylates has significantly supplemented traditional methods of detecting traces.

As a rule, non-porous materials are treated with cyanoacrylate vapors in a special closed plexiglass container, resembling a regular aquarium. To increase the efficiency of detecting traces and reduce the processing time, heating and increasing humidity are used. For this purpose, a portable heater (bain-marie) with a few drops of super glue on a small aluminum saucer and a cup of water are placed in the container along with the samples.

To monitor the progress of the process, a control print made on a clean piece of plastic is placed in the container along with the material evidence. The samples are processed in a closed container for 3 to 10 minutes, or until the control print becomes clearly visible in light strokes. It is advisable to carry out the process in a fume hood. The exact processing time is determined by the development of the control print.

Once fumigation is complete, the samples are removed from the container, usually with the fume hood fan running to reduce exposure of laboratory personnel to superglue fumes. However, despite the ventilation, personnel are inevitably exposed to cyanoacrylate fumes. Although superglue fumes are not claimed to be carcinogenic or toxic, they may be irritating to the eyes and respiratory system.

Once fumigation is complete, the marks can be treated with powders and chemical dyes for subsequent observation using forensic and laser light sources, and photographed for further work.

In the early nineties, the well-known American company 3M proposed an original system called FIVIS * for the rapid detection of fingerprints using cyanoacrylates not only in the laboratory, but also directly at the scene of the crime. It was assumed that now an expert or other trained police officer would be able to quickly detect fingerprints using a special gas burner and disposable cartridges with superglue.

* FIVIS — abbreviation for the English FIngerprint VIsualization System, which means “visualization (i.e. detection) of fingerprints”.

The smoker itself was remarkably reminiscent of a 3M autonomous gas soldering iron, familiar to serious radio amateurs at least from the relevant catalogs. This is not surprising, since both devices were made on the basis of the same portable gas burner. During operation, a cartridge with dried cyanoacrylate was installed on the tip of the burner (photo 2). After the gas was ignited, the burner began to emit heat, warmed up the cartridge with super glue, and cyanoacrylate vapors began to be released from it quite intensively.

The cartridge was a stepped thin-walled metal cylinder filled with metal wool soaked in hardened superglue. Each cartridge was enough for about 5 minutes of continuous work. In addition to the usual cartridges, there were cartridges containing a fluorescent dye. For obvious reasons, when observing the luminescence of the detected traces in ultraviolet rays, the contrast of the image is significantly increased. The FIVIS 3M device was easy to use, but, according to the manufacturer, some training was needed to use it successfully. The first operational tests showed that the quality of the traces detected depended to a large extent on the operator’s qualifications and the conditions of his work: directly at the scene of the incident or in the laboratory.

Photo 2. Cyanoacrylate cartridge on the smoker.

The expert needed a certain amount of time to acquire the appropriate skills for working with different types of traces on different trace-receiving surfaces. In particular, it was strongly recommended to practice working with the burner in different modes, for example, 30 seconds of short fumigation, 3 minutes of medium intensity processing, 4-6 minutes of deliberate redevelopment.” This allowed the expert to feel the peculiarities of the process of detecting traces on different surfaces. As he gained experience with the smoker, he set the optimal degree of heating to obtain the best results.

According to the operating instructions, working with the smoker was as follows:

• Using the slide switch, turn on the gas supply: move it to the ON position.”
• Smoothly press the ignition button on the side ledge of the device body and hold it in this position for 3 seconds until the device reaches the operating temperature. This is determined by the glow of the white windows on the metal nose of the smoker. At the initial stage, the burner operation is accompanied by a peculiar whistle. If this does not happen, you should repeat the switch-on at a different value of the gas supply regulator.
• Set the gas supply regulator (temperature regulator) to a position in which the horizontal flow of super glue vapors emanating from the nose of the device is 20 — 30 mm — usually this is position “3”.
• Using special tweezers, install a disposable cartridge with cyanoacrylate on the tip of the smoker. After a few seconds, “smoke” should appear.
• Fumigate surfaces that may contain fingerprints.

Although the natural reaction of the operator was to bring the burner closer to the surface being examined, the fumigate should be positioned at a distance of 20-30 cm from the surface being examined. Otherwise, overdevelopment or background retardation would inevitably occur.”

The processing time of the trace ranged from 30 seconds to 3 minutes, depending on the type of surface and the trace on it. If necessary, the smoker could be switched off and later switched on for repeated processing.

Photo 3. Using the smoker outdoors.

It was also recommended to move the smoker from side to side over the trace being detected. To increase the efficiency of the treatment, a small fan could be placed nearby to direct the flow of cyanoacrylate vapors toward the surface being treated. The fan speed had to be low enough to ensure a slow and even flow.

When using the smoker outdoors (photo 3), especially in windy weather, it was recommended to use a protective screen, for example, a cardboard box in which a hole was made for the smoker's nozzle.

Due to the polymerization effect of cyanoacrylate, the traces revealed were quite durable and allowed processing with any fingerprint powders, as well as their subsequent removal on a fingerprint film.

The FIVIS smoker could also be used to treat various objects in a closed container, such as a regular fish tank. It was only necessary to ensure adequate ventilation and the release of cyanoacrylate vapors. Depending on the type of object, it took 3 to 5 minutes to fill such a container. For these purposes, one replaceable cartridge of cyanoacrylate is usually sufficient. But even in this case, it was necessary to be very careful and not allow the traces to be “covered” by the background.

The FIVIS smoker was able to easily treat the interior of a passenger car. It took 1 to 3 cartridges. Once the optimum density of cyanoacrylate vapors was reached, the interior had to be kept closed for about 15 minutes, after which the car had to be thoroughly ventilated.

There were no special warnings about possible “dangers” in the description of the smoker. Basically, they boiled down to the following:

• Since the smoker and cartridges with cyanoacrylate heat up to a high temperature during operation, they should not be placed near flammable objects.
• The vapors produced by fumigation with cyanoacrylate could have a harmful effect on the respiratory system and even cause an allergic reaction. Eye and skin irritation could also occur.

For this reason, it was recommended to use the FIVIS smoker in a ventilated room, and if necessary, use respirators, safety glasses and gloves. In case of injury, it was necessary to go out into the fresh air, rinse the eyes with plenty of water, treat the skin with a soap solution and also rinse with water, and then consult a doctor.

And so, if you believe the advertising materials, the FIVIS smoker from 3M was presented as a kind of “magic wand”:

• The device fits in the hand and can be used to detect fingerprints on material evidence directly at the scene of the incident.
• With its help, the interior of a car can be treated in less than an hour.
• For the first time in forensic practice, the processes of fumigation with cyanoacrylate and ultraviolet staining of the identified traces were combined in one process.

Samples of FIVIS fumigators from 3M appeared in Russia in the mid-90s. The first experiments in domestic practice on their use to identify fingerprints were conducted by the author of these lines together with Alexander Ivanovich Sheptur, head of the ECO Department of Internal Affairs of Tuapse, Krasnodar Territory, a true enthusiast of his business.

Despite the promising advertising materials of American supplier companies, to our great regret, it was not possible to achieve the stated results: the results obtained were quite unstable, the quality of the traces detected was unsatisfactory each time, and the overall costs were unjustifiably high.

According to available information, similar work was also carried out by American forensic scientists. For example, from June 1994 to June 1995, an experimental test of this fumigator was conducted in one of the forensic laboratories of the US Department of Defense. First of all, the effectiveness of its use in the open air was compared with the usual method of fumigation in a closed space, as well as the level of personnel safety and ease of use.

The first experiments have already shown that an expert working with a smoker at the scene of a crime is forced to process all the supposed locations of possible traces. Considering the short life of cyanoacrylate cartridges, it should be noted that such a “blind” method turned out to be not very convenient in practice and very disadvantageous from an economic point of view.

The apparent ease of use of the FIVIS smoker did not compensate for some of its significant shortcomings:

1. Placing the smoker just a few centimeters away from the surface being treated can sometimes lead to irreparable consequences. For example, drugs are often packed in easily fusible plastic bags and, naturally, may have traces of the drug dealers' hands on their surface. The heat emitted by the smoker's gas burner can easily damage the surface in question.
1. As a rule, control over the release of cyanoacrylate vapors during smoker operation is difficult or completely absent. For example, working outdoors leads to free (uncontrolled) distribution of vapors and their evaporation.

From a safety point of view, fumigation should be carried out under a fume hood. In this case, the operator has both hands occupied: one of which holds the fumigator, and the other the sample being examined, which is quite inconvenient due to the limited size of the fume hood window. Moreover, the fume hood fan quickly removes cyanoacrylate vapors before they have time to react with traces on the surface of the evidence. If the fan is turned off, super glue vapors will escape from the fume hood and affect the operator.

An alternative to this is to work in a well-ventilated area. In this case, the operator should use a special mask to protect the eyes and prevent exposure to cyanoacrylate vapors on the respiratory system. Of course, using a mask makes the operator's work more difficult and increases the overall cost of the process.

3. Another significant drawback of the smoker is the short operating time of the super glue cartridge. In fact, the smoker, set to maximum, evaporates the cartridge in about one minute.

According to the remark of David E. Weaver, the inventor of the FIVIS smoker, made by him in August 1994, the most optimal is the “pulse” method of operation, when the device is turned on for a short time only to warm up the cartridge, and then turned off. This allows you to extend the operating time of one cartridge as much as possible.

True, in order to increase the duration of the smoker's operation, a large cartridge 87 mm long was created at one time. But it turned out to be so large that control over the process significantly worsened. The fact is that the vapor emission zone, for obvious reasons, is located at the junction of the smoker with the cartridge, and not in its spout, as initially envisaged by the manufacturer. The expected increase in efficiency did not happen.

And more about safety precautions. It is known that when liquid superglue is heated to a temperature exceeding 204° C, toxic fumes of hydrocyanic acid are released. With the traditional method of fumigation with cyanoacrylate, when liquid cyanoacrylate is applied to an aluminum plate installed on a portable electric heater (an ordinary bain-marie), the temperature is about 104° — 113° C. Even when using surrogate heaters, for example, an ordinary 100-watt light bulb, a temperature of 154° C is reached.

Back in July 1994, David Kemp, a 3M employee responsible for the FIVIS project, when asked about the possibility of cyanide release during the operation of the smoker, replied that the temperature developed was insufficient to form toxic compounds. At the same time, the smoker tests conducted by him over many years showed that the temperature developed at the tip of the device ranged from 343° to 371° C!

In this regard, 3M specialists stated that since the FIVIS gas burner heats cyanoacrylate in a solid phase in an open space, they did not notice any “traces of cyanides”!

At the same time, independent experiments carried out in the forensic laboratory of the US Department of Defense in the state of Georgia showed:

• the temperature inside the cartridge installed on the smoker with the combustion intensity regulator position “1” was 427° C
• temperature inside the cartridge with the regulator position “3” 574° — 593° C
• temperature inside the cartridge with the regulator position “5” 610° — 630° C
• temperature at the tip of the smoker without a cartridge with the regulator position 1” was 593° — 648° C and 704° C
• the same with the regulator position “5” 704° C

Note: the temperature was measured using a Fluke multimeter (model 8021B) and the corresponding temperature probe at different positions of the combustion intensity regulator.

FIVIS smokers were also tested at a similar crime lab in Maryland and found vinyl cyanide to be present, but the concentration was not high enough to cause concern for the health of personnel when using the smokers under the conditions recommended by the manufacturer's operating instructions.

When using regular cartridges, the highest concentration of vinyl cyanide reached 0.74 parts by volume of vapor per million parts of air, and 2.9 parts per million when using a large cartridge.

It should be noted that in the appendix to the technical description of the FIVIS smoker cartridges, devoted to safety issues on page 2, it was noted that …during their operation, such harmful substances as carbon monoxide (carbon monoxide), carbon dioxide (carbon dioxide), nitrogen oxides and hydrocyanic acid.. are released.

In this regard, it is interesting to refer to the standards of maximum content regulated by the American Association for Occupational Safety and Health in Industrial Plants of the United States. It turns out that for an eight-hour work schedule, the standard is set at 2 parts by volume per 1 million parts of air. For work for 15 minutes, the maximum concentration of vapors is set at 10 parts of vapor per million parts of air.

It is known that superglue vapors have an irritating effect on the organs of vision and respiration. But the irritating effect of superglue vapors “prevents” the dangerous effect of cyanides and begins to manifest itself even before their maximum permissible concentration is formed. In any case, personnel must be immediately evacuated from the work area.

Comments, as they say, are unnecessary…

COMMENT OF TWO FUMGING METHODS

Photo 4

Photo 5

Photo 6

Several fingerprint and palm print samples on glass, plastic and foil were used in a comparative experimental test of the effectiveness of fumigation using the “traditional” method and the FIVIS gas burner.

The trace samples were cut into two parts and processed in the conventional way and with the FIVIS smoker, respectively. The results of the experiments are shown in photos 4, 5 and 6. The samples subjected to “conventional” fumigation are marked with the letter “C” (conventional), and with the use of a gas burner — with the letter “W” (wand smoker).

It is obvious that the traces revealed by the “traditional” method are significantly superior in quality to those obtained with the gas burner.

In addition, sweat and grease traces were applied to the surface of glass samples, which were also processed using the two methods indicated and compared when observed using a scanning electron microscope. It is noteworthy that during conventional processing, traces are revealed in the process of polymerization of cyanoacrylate in the form of «flagellates» (photos 7 and 8), and when fumigated with a burner, in the form of rounded lumps. As a result, a more intense image is achieved with conventional fumigation, which, when subsequently processed with chemical dyes, provides more contrasting traces.

Photo 7. Traces obtained during conventional processing.	Photo 8. Traces obtained during burner processing.

Not the least argument in choosing the fumigation method is its cost. The cost of purchasing a fumigator and consumables: cartridges and liquefied gas for filling it significantly exceeds the cost of liquid cyanoacrylate for working in the “traditional” way.

Thus, the preliminary study allows us to conclude that the use of a smoker to detect fingerprints is justified only when used outdoors directly at the scene of the incident and can only have limited distribution.

But even in this case, unsatisfactory results or even complete damage to the traces cannot be ruled out. Due to the fact that when using a smoker, the quality of the traces detected is noticeably worse than with traditional technology, and the possibility of their subsequent improvement in laboratory conditions also decreases.

When working with a smoker based on a gas burner, certain problems arise related to compliance with safety regulations. It seems advisable to use the smoker to treat the surfaces of large objects that cannot be delivered to the laboratory to detect traces. The combination of a relatively high cost and potential health hazard does not allow us to recommend its widespread use to detect traces.

We could end there, but it is difficult to refrain from the following remark. A year and a half ago, the FIVIS smoker disappeared from the catalog of the above-mentioned Lightning Powder® Co., Inc. And its place was taken by a similar smoker with the emblem of another well-known company, SIRCHIE®*. According to available information, 3M has stopped producing FIVIS smokers…

However, at the last exhibition “Security Technologies-98” at the stand of the company “Kurt Mitterfelner” (Germany) a forensic suitcase with a FIVIS smoker from 3M was presented.

* SIRCHIE® finger print laboratories, Inc., Lightning Powder® Co., Inc. and Criminal Research Product , Inc. are the three largest American suppliers of forensic equipment.