The Effect of Gravitational Attraction and Air Resistance on a Projectile

The study of exterior ballistics is based primarily on the understanding and application of principles of physics. In their book, Shooting Incident Reconstruction, authors Michael G. Haag and Lucien C. Haag discuss the physics and application of exterior ballistic forensics. In this blog post we will review the two primary parameters associated with a bullet’s flight and review the equation responsible for expressing the slowing of a projectile. Read More...
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An Introduction to Exterior Ballistics and the Forensic Application

Ballistics is the science of projectiles and firearms, and the study of the effects of being fired on a bullet, cartridge, or gun. Exterior ballistics also known as external ballistics is the part of ballistics that deals with the behavior of a non-powered projectile while in flight. The flight of projectiles (in this case bullets) must obey certain laws of physics. Scientists and engineers have developed the necessary mathematics to both describe and predict the flight of projectiles through the atmosphere. Read More...
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A Further Look at Collecting Evidence Related to Knots and Ligatures

Dealing with knots and ligatures at the scene of an investigation may seem like a straightforward and obvious task, however great care and observation is required to ensure all knots, ligatures and related evidence are observed and accounted for respectively. Just looking for knots and ligatures at the scene of an investigation may not be sufficient investigation coverage. Good private investigators and forensic knot investigators must be aware of a great deal of knot and ligature related information and be able to apply that working body of knowledge to the scene of the investigation. Private investigators and forensic knot investigators must be aware that knots and ligatures can be utilized for any number of household items, hobbies, recreational equipment and work equipment. Read More...
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Preserving Knot and Ligature Related Evidence

Evidence at the scene of an investigation must be properly handled and preserved, so that it may serve its intended function throughout the course of an investigation. Like any other type of evidence, knots and ligatures must also be appropriately analyzed, handled and preserved,in order to maintain the integrity of the evidence. Due to the complex nature of knot and ligature related evidence, thorough documentation, expert removal and precise handling are required. Private investigators and forensic knot investigators, with their expert body of knot and ligature related knowledge, should be called to the scene of investigation to help ensure all evidence is thoroughly documented, and precisely removed for further analysis. Read More...
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Collecting Evidence Related to Knots and Ligatures

The first step for a private investigator in a criminal defense investigation process is to collect as much information and evidence possible. The collection of relevant evidence is essential for a private investigator, as evidence, properly interpreted, will create a visual retelling of the events. Once evidence is collected, the preservation of the material is also of the utmost importance. Depending on the form and material, evidence can be vulnerable to a number of external factors, including time, weather and other physical elements. Read More...
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Steps to Ensure Scientific Documentation of Photography


Private investigators who utilize both digital and film-based photography should apply procedural steps of scientific documentation to ensure that the information is recorded in a methodical and accurate manner and the raw material is appropriately preserved. This blog post will examine some of the foundational steps necessary for the scientific documentation of photography.

Files and negatives are the raw material of photographic documentation and are thus critically important to any investigation and its outcome. If files or negatives are lost or damaged they cannot be replaced, so the appropriate preservation is paramount.
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Common Core Analysis Techniques Part 2

Richard J. Heuer Jr. and Randolph H. Pherson identify seven common core techniques every analyst should master and utilize in their book, ‘Structured Analytic Techniques for Intelligence Analysis’. The seven techniques identified by Heuer and Pherson are Structured Brainstorming, Cross-Impact Matrix, Key Assumptions Check, Indicators, Analysis of Competing Hypotheses, Premortem Analysis and Structured Self-Critique and ‘What If? Analysis’. Heur and Pherson believe that analysts should not only be aware of these techniques, but they should also be familiar with their appropriate application and benefits. In the previous related blog post we explored Structured Brainstorming, Cross-Impact Matrix, Key Assumption Check and Indicators. In this blog post we will examine Analysis of Competing Hypotheses, Premortem Analysis and Structured Self-Critique and ‘What If? Analysis’. Read More...
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Common Core Analysis Techniques Part 1


A good analyst must command a strong working knowledge of numerous analysis techniques, including their respective strengths, weaknesses and appropriate application. While some analysis techniques are more commonly utilized than others, it is important for a good analyst to properly understand common core techniques and their applications.

Richard J. Heuer Jr. and Randolph H. Pherson identify seven common core techniques every analyst should master and utilize in their book, ‘Structured Analytic Techniques for Intelligence Analysis’. The seven techniques identified by Heuer and Pherson are Structured Brainstorming, Cross-Impact Matrix, Key Assumptions Check, Indicators, Analysis of Competing Hypotheses, Premortem Analysis and Structured Self-Critique and ‘What If Analysis’. In this blog post we will explore Structured Brainstorming, Cross-Impact Matrix, Key Assumption Check and Indicators.
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How CSI Sensationalizes Evidence and A General Overview of the Scientific Method

The behavior of jurors in a criminal trial, and whether they acquit or convict is often a source of confusion and entertainment to all parties involved including the general public. Today the behavior of jurors is sometimes attributed to ‘the CSI Effect,’ which is the result of popular television programs that are based on fictionalized situations involving the criminal justice system.
Jurors interviewed after trials, where there was an acquittal, sometimes expressed doubt in the validity of the case if there was no hard forensic evidence presented or observed during the trial. These jurors also deemed eyewitnesses potentially untrustworthy and doubted their ability to recall the events in question while under scrutiny. Unfortunately, the CSI television programs are not an accurate or scientifically valid representation of potential real life scenarios, and their influence should be highly discounted. The effects of CSI television programs have even been deplored by the American Academy of Forensic Science, which addressed the negative influence in a newsletter.
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Structured Analysis: Methods and Practice

In the beginning of ‘Structured Analytic Techniques for Intelligence Analysis’, Richards J. Heuer Jr. and Randolph H Pherson identify four broad categories of analytic methods. These identified approaches are distinguished by the name of the analytic methods used, the type of quantification if any, the type of data that are available, and the type of training that is expected or required. Each of the four categories is distinct, however at times, there is considerable overlap amongst particular categories. These four broad categories are Expert Judgment, Structure Analysis, Quantitative Methods Using Expert-Generated Data and Quantitative Methods Using Empirical Data.
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