Bloodstain : the Crime Scene - Essay Example

Details Blood Stain Pattern Analysis Part One – the Crime Scene A homicide case in New York was investigated atthe request of the office of the district attorney. The deceased, who was male, was found lying in his bed on the left side with a wound on the right side of his head that resulted from a gunshot. Stains of the blood were found directly on the murder weapon, the victim, the bedding and the wall. Our investigation was intended to determine whether the bloodstain pattern at the crime scene were consistent with the statement that were made by the defendant. Before we begun to examine the crime scene, we gathered as much information as possible from the scene. This was to prevent the destruction of the valuable and fragile evidence such as shoe prints, concealed weapons and bloodstains. We began to scrutinize and examine the crime scene by taking a walk into the trail of the crime scene. Documentation of the crime scene. We preferred to use a video recording in documenting the events in the crime scene because these recordings provide a detail perspective that could not be easily perceived in sketches and photographs (Labe, Terry and Barton, 1983). The recordings was mostly focused on the victims surroundings such as the murder weapon, the orientation of the bed that he was murdered on, the blood stains on the victim and the surrounding environment. We did not made the assumption that the blood belonged to the same victim. In this case, it was possible that some of the blood stains gathered at the scene could have been that of the suspect which might have been caused by self-wounding. We documented some classic patterns at the scene to help with the investigation. This pattern included; cast-off Blood stains, the swipe marks on the victim, pattern transfer and the drip patterns (Labe, Terry and Barton, 1983). We also used photograph to document the events at the scene. This was accomplished before anything could be moved or touched at the scene. The photographs that were taken depicted the overall scene which was then followed by close-up and medium range views of the pattern. We included the scale of measure with the close-up photographs. Similarly, we employed sketches and diagram to indicate the position of the bed in relation to the significant and fixed object in the crime scene. During sketching we did not just focus on the immediate environment from where the impact was identified, but we also sketched the larger surrounding in order to shoot the shooting scene in its proper context. Collection of the Evidence We photographed the blood stains, bullet fragments, bullets and the trigger cases in their place and had their location carefully measured and included in their diagram before beginning the process of recovery. The collection of the evidence stops for a while because the crime scene required us to cut into the wall of the room to collect the fragments of the bullet that had stuck in the walls. We marked the floor at the location of the murder weapon, i.e. the firearm, with a tape and labelled it (Schiro, 2012). In order to obtain biological evidence that could link the offender with the crime scene, we resolved to gather any DNA evidence. In this case, the biological evidence that we obtained at the crime scene was the blood stains on the victim’s body and it was forwarded to the forensic lab for testing. Apart from the blood sample that we found, we also gathered some figure prints and hair at the scene. These two sample was also forwarded to the forensic lab for testing to determine their DNA. During the examination of the scene we were lucky enough to find shoe prints at the scene. This was of great help to the investigation as it could determine the make, size, model as well as the approximated height of the person and his or her gender. Because the crime scene involved a gun, we collect multiple clothing’s from the victim and anyone who might have been at the scene in order to test for the gunshot residue. The approach used to process the evidence In order to come up with a concrete clue on who might have committed the offence, we processed the evidence that we gathered from the scene. The first step that the investigation department took was to analyze the DNA of the blood stains retrieved from the Scene. It was a bit difficult to come up with some evidence from the stains of the blood as most of the DNA results showed that much of the blood samples were of the victim. There was no blood sample that could link the offender or any second party to the crime scene. The forensic department used the Restriction Fragment Length polymorphism (RFLP) DNA analysis. In this analysis the lab technician used a certain DNA sequence that is present in the white blood cells to link the blood samples and its source (Schiro, 2012). Unfortunately, all the blood stain analysis indicated that all the blood sample came from the victim and thus it was quite difficult to determine the offender from these blood samples. However, one piece of evidence seemed to draw us close enough to the offender. The hair samples that were picked from the crime scene showed the DNA of two individuals. The first sample indicated the DNA of the victim while the second sample that was tested showed the DNA of a second party who we categorized as our main suspect. Also, the saliva obtained from the surface of the victims body indicated that it comes from the same suspect who, according to the forensic database, was identified as Mark Lutherfield. After identification of our main suspect, the detectives hunted for him in the streets of New York and arrested him. The forensic department searched his apartment and obtained some clothes in his trash bin, of which we believed he might have won during the day of the act. We test this piece of clothes for any evidence, luckily enough we were able to retrieve some gun residue from the shirt which marched the sample that had been collected at the crime scene earlier on. This was enough evidence to detain the suspect and prosecute him in the court of law. Part Two: Courtroom Testimony Direct examination by the prosecution DE-1: What is your job title, what type of crime scenes have you been processed and how long have you been in your current position?  I am a Crime Scene Investigator (CSI) dealing with forensic testing and analysis of the evidence gathered at a crime scene. I have been in this position for nine years and I have majorly processed homicide scenes that involve gunshots. DE-2: What type of training do you have in this field? I have been trained as a lab technician of the forensic department for criminal investigation. DE-3: How did you get your assignment to go to the crime scene?  We were assigned by the district attorney to investigate the crime scene and come up with concrete evidence to prosecute and sentence the offender. DE-4: When you arrived at the scene, who did you meet and how was the scene secured?  When we arrived at the Scene we found a male body lying on his bed to his left with a gunshot wound to the right of his head, the murder weapon floor covered with blood stains. The bloodstains were also on the victim, the wall and the bedding. To secure the crime scene, we assigned some officers outside the crime scene and used a tape to seal the area and prevent any movement in and out. DE-5: Can you explain to the jury what you mean by processing a crime scene for bloodstain analysis?  In processing a crime scene for blood stain analysis, we collect the blood sample from the crime scene. We then find the victims genetic marker such as the ABO blood type or the genetic profile on the suspect or something that is in the possession of the suspect. Secondly, we find a blood sample with the genetic marker of the suspect on the victim and the carry out the analysis. We collected the bloodstains from the crime scene in order to link the blood sample with the suspect. Cross examination by the defence CE-1: Can you explain how you documented the bloodstain evidence you collected? We used a video camera to document the scene so as to capture the minor details. We also used photographs to capture specific pictures such as the bullet holes, the blood stains on the wall and the victim’s body. Finally, we use diagrams and sketches to come up with the orientation of the crime scene. CE-2: What were you told by the detectives about the crime scene?  The detectives in charge on the crime scene claimed that there might have been a struggle during the act, due to the plenty of broken items at the scene. CE-3: Is it fair to say, you identified and collected bloodstain evidence based on what the detectives told you?  Our blood stain analysis were not based on what the detective told us, but from the forensic results that we obtained from the lab. CE-5: is it possible that cross-contamination occurred at any point in your collection of the evidence or during the analysis of the evidence?  We collected all the evidence which includes those that could have linked the suspect with the murder and those that could not have linked him. We were very careful during the examination of the crime scene to ensure that no cross contamination or interference of the evidence occurred at all. Conclusion Based on all the evidence gathered, it was right to term Mark Lutherfield as the prime suspect of the murder incidence as all the evidence collected directly linked him to the incident. It is therefore fair enough to prosecute him, according to the evidence that was collected. . References Labe, Terry L and Barton P, 1983. Blood stain pattern analysis. Minneapolis: Callan Publishing Schiro G, 2012. “Collection and Preservation of blood Evidence from Crime Scene”. Crime Scene Investigator. 36 (2). 154-557. Read More