Determination of Height from The Angle of Projection of Bloodstains

This is to certify that the NTCC entitled “DETERMINATION OF HEIGHT FROM THE ANGLE OF PROJECTION OF BLOODSTAINS” is submitted as project by Ms. NAVODITA TYAGI B.Sc.(H) FORENSIC SCIENCES during her period of study in Amity University of Forensic Sciences ,AMITY UNIVERSITY,UTTAR PRADESH under my supervision and guidance.

During the entire period ,she was very sincere and has completed the project with lot of hard work and enthusiasm.

I wish her luck for her prosperity and bright future ahead.

Acknowledgement

In this NTCC project, on the topic “DETERMINATION OF HEIGHT FROM THE ANGLE OF PROJECTION OF BLOOD STAINS” ,I place on record my thanks and gratitude to DR. S.K. SHUKLA, Director of AIFS, Amity University, AUUP who supported me in the preparation of this project.

Excellent advice and support of my guide Dr. AMARNATH MISHRA has been really invaluable on the academic level for which I am extremely grateful. Under his guidance I have been able to complete this project.

I am extremely thankful to all the faculties of AIFS for the help rendered support throughout during the course of study and guiding me in the completion of the dissertation. My sense of gratitude and thanks goes to all staff members of administration for their co-operation throughout my course.

Introduction

Blood spatters are the patterns that are created by the blood when it falls on a surface from a certain height during a crime .The examination of location , shape, size and distribution pattern of bloodstain that helps in the analysis of the physical events that took place and the events due to which the patterns are made.

In this study blood spatters were created with the red colour whose viscosity was similar to that of blood drops of red colour were dropped from different – different heights and at different angles too. These were analyzed to estimate the height , angle and volume and the size and shape of the pattern. As a resultant. It was concluded from the study that the droplets from different height different shapes; such as a droplet from 2.5 of height appears small and round while at the same time a droplet from 6 feet of height gives a round appearance with larger diameter including more number of satellites. This analysis of the drops gives estimation about the suspect’s height and the shape estimates about the time of occurrence .it can be helpful in the forensic field of investigation and can be put on the par above of all the evidences for the conclusion.

Blood Spatter

Blood pattern analysis is a forensic discipline which is basically the scientific study of the static events resulting from blood shedding events. It deals with the physics of the blood on the principles of physics like as mechanics and physics of fluid .It includes the examination of the blood location, shape , size and the scattering pattern on the various surfaces such as walls, ceiling, floors etc.

The examination and analysis of such physical appearance of blood which forms a pattern is known as blood spatter analysis. The blood stains often reveal the invaluable evidences during the crime scene investigation.

Bloodstain Characteristics

When a drop strikes the surface ,it forms a circular pattern. The size of the blood droplet depends on the height where it falls , angle at which it strikes the surface and the speed of the droplet and the type of surface on which it is falling like hard and smooth surfaces creates a pattern that is smaller then the rough or irregular shaped surfaces. The circular pattern formed by the drop of blood increases in size when it falls from the height of about one inch to seven feet.

Secondary or satellite spatter is formed when blood droplet falls on a hard surface. These SD satellites surround around the circular blood stain

When a drop strikes a smooth surface at 90 degrees ,it produces a circular blood stain whereas if the blood drop strikes at an angle less than 90 degrees, an elongated pattern is observed.

The shape of the blood drop also helps in determination f the direction of blood stain. If the stain is elongated or elliptical in shape, the tail end/the narrower end of the stain points to the direction of travel of the blood drop.

Comparison between the angle of impact and the direction of travel also reveals the origin of the blood drop.

The angle of the impact of blood spatter is the angle of the blood as it strikes a contact surface. This angle can be determined by taking measurements of the length of the bloodstain and the width of the bloodstains.

Importance of Blood Spatter Analysis

Blood spatter analysis shows various aspects regarding crime scene which helps in reconstruction of crime scene.

It tells us-

1. The origin of blood drop.
2. Distance from origin to the impact.
3. Direction of impact.
4. Type of impact.
5. No. of blows or shots.
6. Position of victim and the offender at the time of bloodshed.
7. Movement of victim and offender during bloodshed.
8. Movement of victim and offender after bloodshed.
9. Impact angle.

Materials and Methodology

Objectives

To study the effect of height ,angle and volume on size and shape of blood spatter.

Estimation of suspect’s height from the shape of blood spatter.

Materials Required

Red colour (Viscosity similar as that of blood),Measuring tape ,Pencil ,White paper ,Droppers ,Protactor ,Camera.

Hypothesis for objective 1:

Null hypothesis (h0): height, angle and volume affect the size and shape of the blood spatte.

Alternate hypothesis (h1) : height, angle and volume does not affect the shape and size of the blood spatter.

Hypothesis for objective2:

Null hypothesis (h0): suspect’s height will be estimated from the size and shape of blood spatter.

Alternate hypothesis (h1): suspect’s height will not be estimated from the size and shape of the blood spatter.

Sample Collection:

The experiment was conducted in the laboratory on the floor(for height) as well as on the wall(for angle)with the help of colour (viscosity same as that of blood).

For the parameter of height: white sheet was placed on the floor and then from different heights i.e. from 2 feet,2.5 feet,3 feet , 3.5 feet, 4 feet, 4.5 feet, 5 feet, 5.5 feet,6 feet respectively coloured drop from the dropper was dropped to make the spatter.

For the parameter of angle : white paper was fixed on the walls and from different heights, colour was taken in the brush and was splashed on walls at an angle of 30,45,60 and 75 degrees respectively. Then the spatters made were observed.

Sample analysis: The samples collected were analyzed for their size and shape on the basis of the sine formula. The size and shape of the spatter formed were analyzed for estimation of height of the suspect and the angle formed.

Before carrying out the analysis , basic knowledge about the blood spatter is required. The knowledge about the size and the shape formed due to the force with which the spatter was made.

Observations and Results

OBSERVATION TABLE NO. 1

HEIGHT FROM THE GROUND AVERAGE DIAMETER(in cms.) OBSERVATION PICTURE

2 FEET 0.7 Round drop with no satellite.

2.5 FEET 1.0 Round drop with no or very small satellite.

3 FEET 1.5 Round drop with very small and few satellites.

3.5 feet

1.6 Round drop with small satellites.

4 feet 1.6 Round drop with small but more satellites.

4.5 feet 1.8 Round drop with large satellites.

5 feet 1.9 Round drop but with larger satellites.

5.5 feet 2 cm Round drop with more larger satellites.

6 feet 2 cm Round drop with much larger satellites.

RESULT:

When the drop of the colour was dropped from a height of 2 feet, the drop formed was small, round with no satellite and small diameter. But when the same drop was dropped from a height of 3 feet ,the drop formed was slightly bigger ,round with very small and few satellites. When the drop was dropped from a height of 6 feet , the drop formed was bigger in diameter with large number of satellites.

Conclusion

In this study, when the drop of the liquid was dropped from a smaller height then the formation of droplet on the surface was smaller in diameter and do not possess formation of satellite whereas the drop of the liquid dropped from a suitable height such as 2 ,2.5,3,3.5,4,4.5,5,5.5,6 feet respectively .The drops formed were larger in diameter and possess bigger including large number of satellites. If the volume of liquid is less , then the drop formed is light whereas if the volume is more, then the drop formed is heavy and dark.

When the drop of the liquid is dropped at a right angle to the surface, the drop formed is circular. When the spatter was made from a smaller height as a resultant the small and blunt spatter were formed . When the spatter was made from a height of 2, 3, 4, 5 feet respectively, the sharp, elongated and long spatters were obtained.

At 4 feet, when the spatter was made at an angle of 75 degrees Celsius , patterned spatter was formed. It was noticed during this study that the droplets of the blood forms different shape and size in every condition. Sometimes , the droplets shape and size also depends upon the surface and the temperature of the environment, which could affect the result. The droplets of blood give estimation about the weapon of offence used in the particular crime. On behalf of which, we can conclusively obtain the modus operandi of the crime. This study was conducted only for the examination of the blood droplets shape and size on the smooth surface such as paper and floor.

The droplets viscosity can also affect the result on present various surfaces. During this study, no real blood was wasted and nobody was harmed.

Null hypothesis for objective 1 was accepted i.e., angle and volume affect the shape and size of the blood spatter.

As well as ,null hypothesis for objective 2 was also accepted i.e., suspect’s height will be estimated from the size and shape of the blood spatter.