International Journal of Volume 2 Issue 2 / 2012 Criminal Investigation 119-125

TECHNICAL INTERPRETATION OF MARKS PROBLEMS SOLVED BY FORENSIC BALLISTICS Iamandi LUCA, PhD Abstract In terms of , the interpretation of traces and evidence throughout on-site examination aims primarily to establish the relationship that exists between them and the offense committed. Such an interpretation is aimed at explaining the origin of traces and found objects, the formation mechanism of different types of marks and traces and the relationship that exists between the traces and the evidence (material means) existing in the field of crime. Correct interpretation of the traces found on site can lead to the elucidation of many problems posed by criminal investigation: the nature of the crime committed, the time and place of commission, the operating mode, the number of participants, the actions or inactions of the perpetrator after the crime, etc. Most times forensic ballistics provides solutions both to establish exactly the weapons used in criminal activity and to elucidate the circumstances related to the author, , participants, victim, etc. All these are related to ballistic expertise.

Keywords: firearms, ballistic, technical interpretation

Solving problems with ballistic expertise weapon in the legal sense, the Judicial ballistic expertise, as part category that fits the gun; of forensics, shall be performed in a - What is the type, model and caliber of specialized laboratory1. the ; which is the serial number The request for expertise shall be of the fire arm; forwarded to the institution where the When the inscriptions stamped on laboratory functions and not directly to a the gun have been removed, chemical person. electrochemical or ferromagnetic methods The head of the institution will should be considered to reveal them. nominate the specialist who will perform - status of the firearm. the examination, in relation to the nature b) On firearm use use: and the complexity of the work and the - evidence to prove recent firing; work load of each subordinated expert2. - possibilities to fire a faulty weapon; The questions that the experts must - possibilities to fire without pulling the answer should only cover very specific trigger; aspects, and can not extend to matters - the weapon’s operating status, caliber outside their competence (legal and effectiveness of a crafted weapon; classification, for example). - existance of traces of additional In case of infringements of the factors of firing on the gun barrel; weapons and ammunition laws, the - distance and direction of the shot, following main issues can be cleared by possibly the victim’s and the drawer’s ballistic legal expertise: positions; a) On weapon: - if a shot hole is the entry or the exit; - if the device under examination is a

http://www.ijci.eu eISSN: 2247-0271 119 TECHNICAL INTERPRETATION OF FIREARMS MARKS PROBLEMS SOLVED BY FORENSIC BALLISTICS - if the victim was hit by a ricochet or After the shooting, so after leaving direct fire; the barrel, the bullet goes back to its - type, model and brand of the weapon original size or suffers some longitudinal that was shot after marks on the tubes deformation. or on the bullets under consideration; The barrel interior construction is - if tubes or bullets from the crime precisely indicated by the rifling grooves scene were fired or not by the gun marks on the bullet. provided for test firing3; The rifling characteristics (the - if the gun provided for test firing has distance between the grooves) and the been used for other attacks. twist rate provide information on the type, c) On ammunition: brand and model of the firearm. - series, size, model, type of bullet and For example, if on the bullet there tube; are no transversal marks and there are only - qualitative state of the shell; longitudinal marks, either there was a gun - if they were made industrially or with a strongly corroded5 barrel, or handicrafted; unnapropriate bullets have been used. - if the shot ammunition shows Thus on site can be found similarities to the comparison model;4 deformed shells or bullets or even broken d) On the : ones. - if a silencer was attached to the gun; This can be caused either by use of - the technical features of the silencer; a firearm with the barrel cut off or a - if it was made industrially or normal gun but when the bullet hit an handicrafted. obstacle and reached the target via Ballistic expertise can also solve ricochet. other issues i.e. acoustic examinations In case of shells found on site, their (examination of the sound traces of the size, format and weigh will indicate the shot, of the arming and of the percussion). type of the used firearm: rifle, pistol or revolver. Establishing the type, model and brand Note that the shell, its neck and its of the weapon that was fired internal diameter always reveal the firearm caliber. The bullets and the shells found on At the outbreak of fire, due to gas site can supply valuable details. pressure, the cartridge case and its neck Thus, the bullet diameter - in the thickest are slightly expanded, causing a diameter part – usually indicates the weapon’s increase. caliber. If expansion is more pronounced The explanation is that the bullet, and the neck is more or less cracked it can the cartridge component for a particular be appreciated that a smaller caliber bullet weapon, has a size of 0.2 - 0.5 mm larger was used. than pipe size. The following table shows the For this reason it can not be bullets and cartridges cases characteristics introduced into a firearm neither before that can help determine the make and nor after the shot. caliber of firearms.

120 International Journal of Criminal Investigation, 2, 2, 119-125 Iamandi LUCA

Nr. Cartridge Caliber Length ( mm) Weight (grams) Crt (mm) cartridge bullet Case cartridge bullet case 10,2- 1 For pistol 7,62 34,7 14 24,5 5,45-6,7 1,57-1,7 11,1 Model

1933 2 Standard for 6,35 23,0 12,6 13,7 5,3 3,3 2,0 Browni

ng 3 Standard for 9scurt 24,7 11,5 17,4 9,5 6,0 3,25 Browni

ng 4 Parabbelum 7,65 29,5 15,0 21,5 10,5 6,0 4,14 5 Parabellum 9 29,5 15,0 19,0 12,5 8,0 3,15 6 Label for 8 36,5 26,5 15,7 12,0 7,8 4,0 revolver 7 Colt,md 1911 11,43 32,4 16,3 22,8 19,0 12,9 5,8 Rifle with 8 7,62 77,16 28,6 53,0 21,75 9,6 9-11 light bullet 1908 Russia

When the specialist or the expert is - The barrel pipe thickness; presented with a less known firearm it - The number, the orientation and the could be difficult to establish its make, size of the grooves. model and type. It can be concluded that both the Firstly he will examine the construction of the gun parts which leave inscriptions and the signs of the producer. tool marks on the cartridge case and their Along with the gun serial number the dimensions, including their positioning, firearms may present many inscriptions can lead – in most cases - to accurately with various meanings, for example the establish the fire gun model. firearm name, the caliber, the manufacturer’s name. Functioning status of the fire gun Secondly, especially when the above mentioned inscriptions are missing, The issue of establishing the state he will proceed to establish the technical of operation of the weapon comes up when and constructive features of the firearm. the person who fired claims certain defects The technical details of any firearm of the firearm. consist of: Given that research of this kind is - Total length; very difficult, forensic practice - Weight with and without cartridges; recommends that the examination of the - The length of the bore; gun is run in a certain order, using every

http://www.ijci.eu eISSN: 2247-0271 121 TECHNICAL INTERPRETATION OF FIREARMS MARKS PROBLEMS SOLVED BY FORENSIC BALLISTICS weapon’s instructions provided for grip the breech is pulled back and then examination. released. One then checks if the breech The firearm should be examined came back to the initial position and if the mounted as well as dismounted. cartridge was pushed into its chamber7. Examination of mounted firearms When the hammer is blocked with is performed to determine the state of the safety catch and the trigger is pulled, maintenance of parts and their functioning. the trigger must not move back and the It is recommended that a breech should not move. roentgenography or a gammagraphy is The last check is aimed at performed before the gun is dismantled to establishing whether the firing avoid accidents, in case the firearm is mechanisms work well. Thus we check if, loaded or blocked. when pressing the trigger the cock is easily The photography will indicate the released from the ‘armed’ position. When state and the way that the gun parts are no more pressure is applied on it, the combined. It is necessary to establish the trigger comes back to the initial position. amount of pressure that needs to be Examination of dismantled applied on the trigger to determine the firearms. Each component part will be onset of the lock. This is determined using examined separately. Firstly we check if a dynamometer or a weight hanging on the the parts have the same serial number. The gun’s trigger. The lowest degree of barrel examination – after it is wiped with pressure required for a well functioning clean cloth – is aimed at establishing gun should not be below the minimum channel defects: shown in the tables or indicated by the - missing chips, indenture, pores, bigger manufacturer. or smaller hammering, corrosion of The examination of the mounted metal; weapon is mainly aimed at establishing: - rounding of the corners of the grooves - the amount of pressure that needs to or lands, visible especially on their be applied on the trigger to determine edges; the onset of the lock; - transverse dark dilatation, seen as a - if the gun’s surface presents rust or continuous or interrupted ring; scratches; - spots formed by ferric oxides, which - the presence or absence of cracks in look like small dots located on the the components; interior of the barrel; - if the ejector rod and the hammer head - traces of ferric oxide -superficial dark are moved or not; spots - remained after removal of - the state of the charger support clip, if rust8; it holds the charger in the grip even - linear scratches sometimes with when it easily comes out of the slot6; corroded edges; - pushing the cartridge from the loader On checking the breech one should into the cartridge chamber; observe: if the firing pin and the hammer - the functioning of the safety spring are moved, if the hammer block is mechanism. worn, the wear of the pin; the ease of Thus, the charger is loaded the with movement of the hammer in the channel, exercise cartridges and is inserted into the the wear of the hammer, if the hammer top

122 International Journal of Criminal Investigation, 2, 2, 119-125 Iamandi LUCA

is pushed back by the spring and goes to the rear wall of the seat due to its own behind the front wall of the lock; if the weight and introduces the cartridge, and exterior end of the extractor is pushed by then slides back and hits the primer the spring towards the center. causing the shot. When examining the firearm and An accidental shot can be produced the hammer mechanism one should check: without pressing the finger on the trigger, the state of the springs, if the ejector’s rod by simply hanging the trigger on some is worn, the usage of the safety catch and prominent object, for example when sprin, the wear degree of the firing pin. hunting, by accidentally pulling a twig in On the hammer one should look at the the forest with the trigger. hammer spring assembly for a possible To certify that accidental shooting flattening of the metal or roundening of the took place, experimental firings should be safety catch edges. performed. On checking the gate pin one should observe the wear of its edges, of the Examiners conclusions point and of the spring and if this stays The expert may formulate one of tightly in its place. the following conclusions: The experts in the field of forensic a) clearly - positive, respectively: "the ballistics are facing an important problem presented firearm is a pistol that should be regarded: expressing their _____model______, caliber and it opinion on the possibility of firing a is in working order"; damaged weapon. b) clearly – negative, such as: "the The firings without pressing the trigger presented firearm is a pistol ______., usually occur due to the wear of a part: model______, caliber 'and not - the general wear of the outer surface ______“. of the lock concurrent with the inner c) of probability, for example: "the surface of its seat; presented firearm is a pistol ______, - bending and weakening of the trigger caliber ______and it is, probably, spring; in working order" ; - wear of parts that keep the hammer in d) of impossibility, like: "the model of the ‘armed’ position; the examined firearm cannot be - weakening of the hammer spring; determined” Often there is the possibility of accidental firing with a gun in good The status of the ammunition working conditions. Accidental firings with a good gun generaly occur The forensic examination of as a result of reckless or negligent use of ammunition is aimed at establishing the it. type the model and the manufacturing year The ballistic investigation should of the cartridges based on the reveal the characteristics of the firearm characteristics and inscriptions of the that allow the accidental firing. For manufacturer present on the rim of the example, when the automatic loaded gun cartridge case9. doesn’t have the safety on and falls with a) Laboratory technical its head to the ground, the lock falls back examination of ammunition

http://www.ijci.eu eISSN: 2247-0271 123 TECHNICAL INTERPRETATION OF FIREARMS MARKS PROBLEMS SOLVED BY FORENSIC BALLISTICS The laboratory examination of - the formation mechanism of the ammunition is aimed to establish the marks left by the grooves of the barrel followings: on the bullet; - the status of the cartridges and if they - if a bullet and a case came from the can be used for shooting; same original cartridge, the need of - the cartridge model of the bullet; such examination arises especially - the manufacturing serial number and when the found bullet does not have if all cartridges cases are from the rifling marks to enable the same serial; identification of the used firearam; - if the metal piece is a deformed bullet - which of the cases or the bullets was or a part of it; if it is a bullet the type shot firstly; and model of the bullet should be - if the cases or the bullets are mentioned; standardized or replacements for the - the cause of the bullet deformation; respective firearm. type and model of the bullet; b) Physical and chemical - if certain cartridges or lead are similar examination: to the ones presented for comparison; After the examination of the powder - if the materials used for loading marks left by the shot ammunition, all hunting cartridges (tubes, lead shots, particles found on the barrel and on the pellets, caps, powders) are similar to crime scene objects should be gathered for those presented for comparison; the physical and chemical examination10. - if the primer was fixed in the case The following aspects should be with a special device; clarified: - if the lead shots are handicrafted; - type of powder under examination - if the handicrafted shots were made (black powder – with smoke – or with an instrument; colloidal particles – smokeless); - if some lead shots, their made and - if any bullet came out of the examined their chemical structure are similar to firearm’s barrel; those presented for comparison; - the type and composition of the - the characteristics of the materials powder used with the examined extracted from a wound, during firearm; this can be identified by the surgery or during autopsy, or found at unburned or burned remains of the the crime scene; powder inside the barrel, on bullets, - the paper discs that keep the lead shots on tampering or obstacles closer to the in the cartridge before the firing firearm; (usually these are destroyed during the - if the powder load from the cartridges shot and rarely can be analysed); is not in excess, if the cartridges are - the use of the tracks from the burnt properly loaded and if they can be cases, their characteristics and their fired without damaging the barrel. To significance; solve this issue it is necessary to - the type and model of the fired establish the powder brand and the firearm; quantity of powder contained by each - if the cartridge was shot from the cartridge, also the correlation between examined firearm; the powder weight and the shots

124 International Journal of Criminal Investigation, 2, 2, 119-125 Iamandi LUCA

weight and also the degree of pressure - the length of time passed since the placed on the powder by the tamping shot came out of the barrel for a smokeless propellant;

1 Art. 118 alin 2 si art. I 19 alin 2 din Codul de procedura penala; 2 V. Berehesan, Cercetare penala (Criminalistica - teorie si practica). Indrumar complet de cercetare penala, Ed. lear, Bucuresti 2002, p.220. 3 Tratat practic de criminalistica, vol. I, Ministerul de Interne, Bucuresti, 1976, p. 289. 4 V. Dongoroz s.a., Explicatii teoretice ale Codului penal roman. Partea speciala, Vol. IV, Ed. Academiei, Bucuresti, 1972, p.329. 5 Due to oxidation, the pipe could not give the bullet the spiral motion specific to rifled barrel weapons. 6 V. Berchesan, M.Ruiu – Treaty of Criminalistics, Little Star P.H., București, 2004, p.43l. 7 Under the pressure of the magazine and weight pressing on the clip button 8 V. Macelaru – Forensic Balistic, Ministerul de Interne P.H., Bucuresti, 1972, p.lII 9 V.Miicelaru, Hie Vasiliniuc, loan Daday - "Tratat practic de criminalisticii", Serviciul Editorial și Cinematografic, Bucuresti, 1980, pag. 158-174. 10 Practical Treaty of Criminalistics, vol. III, Ministerul de Interne P.H., București, 1980, p.174

http://www.ijci.eu eISSN: 2247-0271 125