Variations in the Impact Spatter Patterns due to Blunt Weapons Inflicted by Different Gender and Age Groups

Bloodstain pattern analysis makes use of the mechanics of bloodstains to estimate the time, nature and the sequence of events at the crime scene. In this study, a quantitative methodology was developed which includes manually calculating the average size of the bloodstains and the synthetic bloodstains to distinguish the impact stain patterns created by different gender and age groups using the two blunt weapons. Impact stains were created by hitting sponges soaked in blood and synthetic blood using a hammer and a cricket bat. A smaller bloodstain size was observed of the group of males aged between 18 to 30 years. Greater amount of spatter and the distribution of the blood spatter were observed with the bat as compared to hammer due to larger surface area of bat. Cast off patterns were studied and were observed to be produced only by the bat which can be attributed to its higher surface area. Results showed difference in the bloodstain diameter produced from human blood and synthetic blood evaluating if the synthetic blood is suitable for use, as well as variation in the average stain size between produced by the four groups using both the fluids.

Forensic Investigation of Bullet Holes for Determining Distance from Glass Fracture Analysis

The study of glass fracture patterns has been of long interest to the forensic community. Fragments of glass can be significant evidence found in the investigation of various types of offenses especially where armed violence is involved on automobiles. Figuring out, whether glass fragments present on crime scene share the same origin as per glass that has been hit by a projectile or any substrate, is quite a success to an examiner because that further leads to the investigation of how and by which means it has done. Holes occurred in the glass at the crime scenes have much importance and many attempts are taken to investigate the properties of these glass holes to find the type, speed, and angle of the projectile which probably produce the hole. For highvelocity projectiles including bullets, these bullet holes in glass can exhibit certain features and fractures. The objective of this research was to determine the distance of shooter from the bullet hole on glass used in automobiles. Bullet holes were prepared and different parameters of glass fractures like bullet hole diameter, cone fractures radius, cone fractures diameter, radial, and concentric fracture count were considered from both front and the backside of the glass. These parameters were observed and analyzed to determine the dependency of these parameters on the variable “distance”. The consistency found in the measurements to conclude our results were checked by goodness of fit test. The study bears great significance as it could lay down a foundation to set a standard parameter to estimate distance of bullet hole from shooter in firing incidents involving glass fracture. This will provide a blueprint to crime scene investigators in order to reconstruct the crime scene for understanding and to take investigation to logical conclusion.

Touch DNA; A Quantitative Study in the Perspective of Forensic Science

“Touch DNA” is a DNA obtained from biological material transferred from a source to an object or a person during physical contact. Touch DNA came into notice after the research work of Ronald van oorschot, he focused on DNA from fingerprint. We usually use the “Swabbing” and “cutting out” Technique for collection of Touch DNA. Organic method of extraction is most favoured, followed by RT-PCR for quantitation of DNA. Belonging’s used in day-to-day life holds an ample amount of DNA like Brush, Smart phone, Mask, Toothpicks etc, which is quite sufficient to generate a DNA profile of any individual. It can be a very valuable source to establish the identity and individuality of any person in the field of forensic science.