Csi can you predict the splatter
You will determine the angle of impact of just 5—6 spots on the walls. Mark the spots that you are measuring in order to keep track of them. Calculate the angle of impact for each spot using Equation 1, below. By measuring the length and width of the wide part of each spatter mark, you can determine the angle of impact.
Record all data in your lab notebook. Equation Teaspoons of blood added to sponge. Angles of Blood Spatter Marks. At the end of this experiment we analyzed and observed our data we conclude that different blood spatters can give slot of information. The results in this experiment can be life-death important in a crime scene investigator. Blood spatters found in a crime scene can be used to find the "bad guy" or the position the person died in.
It would also be great to determine all this including more surfaces to drop blood on, or different temperatures or different angles. It was determined in this experiment that the blood spatters in a scene can tell a lot.
I learned how to take the angle of blood spatters I performed. I also learned that if I were not the one who performed the experiment I would know how to determine the position and the angles from where the blood was hit, Over all I learned a lot of what the criminal justice career would be like. The real life applications for this project are very useful. In fact this apart from being a simple experiment it can solve murders. Or the CSI would also figure out the way the person died, or how long they were in the floor, or from where they were hit all depending from the blood spatters.
This experiment is used basically everyday when people are killed to find out who the killer is. Some further research i would perform to improve this experiment would be using a real fake human size doll with blood to see and experience the way a person bleeds to death or how they are murdered.
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If this ratio comes out to be. If the ratio comes out to. The texture of the surface that the blood lands on affects the shape of the blood pattern too and detectives have to take that into consideration. Glass, metal, and other smooth, hard surfaces tend to yield blood stains that are rounded. Hard rough surfaces like wood or paper tend to produce blood stains with irregular, jagged edges.
Soft surfaces, like clothing or carpet, absorb the blood and make the edges spread more. Detectives also look at how dry the blood is. Blood begins to dry and clot within 15 minutes depending on factors such as heat and humidity Humidity is the amount of water vapor in the air. The outer edges of droplets tend to dry first and a completely dry droplet may leave a dark ring. How dry the blood is gives the detectives an idea of how long ago the attack happened.
Detectives look at other factors too such as whether or not the blood contains bone or tissues matter which indicate a high impact splatter. They look for voids or blank spots which may indicate something else a person maybe absorbed the blood spatter and then left. They call this shadowing or ghosting. You have to be careful with this one. You can hurt yourself with the hammer and screwdriver which come to think of it, would add a bit of realism to the experiment.
You may also want to try placing the sponge at various distances from the wall and take measurements. Detectives use the knowledge they gain from blood spatter analysis to figure out how the blood pattern was made and hence, how the person who bled was injured, where they were standing when injured, how long ago the crime was committed, and so on.
They take pictures of the blood stains, write down lots of notes, and measure the blood stains that they find. All of this information called evidence by the CSI buffs is taken to a lab where it is studied so the detectives can reconstruct the crime. Below are the types of blood spatter patterns the detectives look for. Low velocity spatter — results from low impact blows.
These often occur after the victim is injured, for instance when they are walking around after the attack and dripping blood on the floor. Droplets are about. May be larger if they are tall or walking on a tightrope. Gunshot spatter will vary depending on the caliber of the gun, where the victim is struck, whether the bullet exits the body, distance between the victim and the gun and location of the victim relative to walls, floors and objects.
Typically, forward spatter is a fine mist and back spatter is larger and fewer drops. Back spatter from a gunshot wound on a steering wheel. Cast-off - results when an object swung in an arc flings blood onto nearby surfaces. This occurs when an assailant swings the bloodstained object back before inflicting another blow.
Analysts can tell the direction of the impacting object by the shape of the spatter tails point in the direction of motion. Counting the arcs can also show the minimum number of blows delivered.
Cast-off spatter patterns from a pipe and a pool cue. Arterial spray - refers to the spurt of blood released when a major artery is severed. The blood is propelled out of the breached blood vessel by the pumping of the heart and often forms an arcing pattern consisting of large, individual stains, with a new pattern created for each time the heart pumps.
Expirated spatter - is usually caused by blood from an internal injury mixing with air from the lungs being expelled through the nose, mouth or an injury to the airways or lungs. Expirated spatter tends to form a very fine mist due to the pressure exerted by the lungs moving air out of the body. Small air bubbles in the drops of blood are typically found in this type of spatter. Some bloodstains are latent, meaning they cannot be seen with the naked eye. Investigators can use chemical reagents such as Luminol to find and photograph latent bloodstains.
Luminol reveals latent bloodstains left on a sink. A crime scene where bodily injury has occurred is likely to have some amount of bloodstain evidence present; however, the amount will vary depending on the circumstances of the crime.
The type of injury inflicted and the amount of force used will determine the volume and pattern of bloodstains:.