1. What is ballistics?
Answer: The word “ballistics” refers to the following: internal ballistics, which describes a missile’s behavior within the barrel; external ballistics, which describes the trajectory the missile follows from the muzzle to the target; and terminal ballistics, which describes the impact of the bullet on the target. Seldom are these issues relevant to the study of forensic guns.
Also Read: 100 MCQs on Forensic Ballistics
2. Is it possible to determine the weapon’s precise make and model through examination of a fired bullet?
Answer: Possibly, but not very likely. Thousands of land and groove widths are provided by the Crime Laboratory Information System (CLIS) dataset on General Rifling Characteristics. Although it takes some effort, it is feasible to identify the manufacturer and model of a weapon from these measurements. It isn’t very useful, however, when looking into crimes.
3. Doesn’t every bullet that passes through a rusty barrel alter its properties?
Answer: It depends on how much rusting there is. While extreme rusting may prevent subsequent bullets from matching, light corrosion will not significantly affect the distinctive stria.
4. Is it possible to compare the first and hundredth bullets fired from the same barrel in forensic ballistics?
Answer: The answer to this question must be “most definitely yes,” provided that the barrel has not been harmed by rusting or any other external influence, such as excessive use of steel wool and cleaning with a steel rod. All firearms examiners should get training on this kind of comparison.
Wound Ballistics: An Overview
5. Will bullets fired via two identically made and model firearms have the same properties?
Brief History of Forensic Firearms Identification
Answer: The same class features will apply, meaning that the groove profile, depth, twist direction, number, and calibre will all be the same. The unique qualities won’t.
6. Is it accurate to say that bullet matching in Forensic Ballistics is not an “exact science,” like fingerprint analysis, which needs sixteen points of similarity?
Answer: Something along the lines of “I don’t know what exactly the term “precise science” means; maybe one should explain.” Should you deduce that an “exactness” of 16 points of resemblance, then what about 15, 17, or 63? Therefore, it cannot be assumed that the choice of 16 lends the topic some magical attribute of an “exact science,” since there is no logical, analytical, or statistical justification for it. There are sometimes hundreds or even thousands of concording sites in striation matches, which make up a valid identification. Since these matching lines are not tallied or given a random number, this kind of analysis is just as precise as fingerprint analysis.
7. Who is in charge of collecting the GSR samples?
Answer: The officer on the stand should have ideally taken them, and he should be prepared to explain any potential contamination. If not, the crime scene investigator who collected the samples will have to be called to testify.
Gunpowder or Black Powder
8. What safety measures have to be implemented to guard against any contamination of the exhibits?
Answer: The expert witness should ideally not have regular interaction with firearms. If not, he would have to prove that he had done all possible to avoid contaminating himself. This would include taking a shower, cleaning one’s hair, changing into new clothing, and donning disposable coveralls and gloves with a hair cover. Before taping the suspect, control tapings must be removed from both him and the disposable gloves. It is necessary to swap out the gloves and, ideally, the coveralls for every recorded topic.
Citation: Brian J. Heard, “Expert and Cross-Examination Question Qualification,” 2008, https://doi.org/10.1002/9780470694589.ch9
