Form follows function: Applying photographic content analysis to forensic firearm identification.

Drawing forensic conclusions from an image or a video is known as "photographic content analysis." It involves the analysis of an image, as well as objects, actions, and events depicted in images or video. In recent years, photographic depictions of objects suspected as illegal firearms have substantially increased, appearing on CCTV surveillance footage, captured by mobile phones and shared on social media.

Photographic Image Comparison of Vegetation.

Images and videos are common types of evidence in crime scene investigations and laboratory analysis. Images may be taken by the suspect and/or by crime scene investigators and may serve as crucial elements in forensic laboratory analysis. Forensic photographic image comparison is the process of comparing one or more objects or persons in photographs/images when at least one image is known to be related to a crime.

Photographic comparison of surface topography as a viable solution when physical match is challenging.

Physical matching methods are a family of well-known methods that are utilized in order to determine whether two pieces of a tearable/breakable material used to be one object. When performing physical match of polymers, it is sometimes difficult to reach an unambiguous conclusion. This is due to various reasons.

Friction Marks of Stabbing Tools in Tires.

When receiving a stabbed tire for examination, forensic toolmark examiners can determine whether a suspect tool was used in a specific crime based on class-characteristics and individual-characteristics marks that have been left by the tool on the tire. This study discusses friction marks and their forensic value during the examination of a punctured tire. The term friction mark refers to the noticeable mark around the penetration area on a tire's surface.

Using headlight patterns in vehicle recognition.

Crime scenes are frequently poorly lit, making it difficult to recognize and identify implicated vehicles that have been caught on film or photographed during incidents. This paper explores vehicle recognition capabilities in dark images, specifically as when a vehicle's headlights are on and are projecting light onto a flat vertical surface. In this study, the headlight reflection patterns of 68 vehicles were photographed and analyzed.

A new method for opening quartz halogen light bulbs in vehicle accident investigations.

After a car accident, it is an important forensic task to evaluate the status of the vehicle's lighting at the time of impact. In some cases, the bulb has to be opened up to allow proper examination of the high and low beam filaments. Quartz halogen pressurized bulbs are both rigid and brittle and their internal pressure makes them likelier to explode.

Effect of Cutting with an Abrasive Saw on Swarf Composition.

Crime scene investigators are often asked to examine swarf from break-in sites and compare it with swarf found on a suspect. Occasionally, elemental composition of swarf from these two sources does not match. It is generally assumed that cutting metal does not induce changes in chemical composition.

Improve Toolmarks' Impressions in Soft Wax.

When the forensic toolmarks laboratory receives for examination and comparison a tool that is suspected of having been involved in a crime, the expert performs tests designed to determine whether or not the specific tool generates the same toolmarks as those found at the crime scene. This is performed by testing tool striation on a piece of soft metal, such as lead, and examining the marks left by the tool. Studies have shown that wax may be an optimal material for this purpose.

Toolmarks made by lathe chuck jaws.

This paper presents a forensic method to evidentially tie a workpiece with a specific lathe. Examining using this method can prove or exclude a connection between the two. The importance of this method is mostly due to the growing trend among lawbreakers of manufacturing improvised firearm parts using machining processes.

Bolt Cutter Blade's Imprint in Toolmarks Examination.

Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object.

A physical match of a metallic chip found on a bolt cutters' blade.

Bolt cutters are known as devices which are used for cutting hard objects and rigid materials such as padlocks and bars. They are commonly used in instances of forced entries. In this case study, a bolt cutter was found in the car of two suspects in a grocery burglary.

The class characteristic mark of the H&M Mul-T-Lock picking tool in toolmarks examination.

Mul-T-Lock is a high security lock cylinder distinguished by the use of a telescoping "pin-in-pin"-tumbler design. Picking the Mul-T-Lock cylinder with a traditional picking tool is highly complicated because it can get stuck between the inner and outer pins. The H&M Mul-T-Lock picking tool was designed to overcome this problem and facilitate the picking of the "pin-in-pin" cylinder.