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Crime Scene Investigation
What is Crime Scene Investigation?
Crime scene investigation jobs have been popularized by several hit crime shows on TV. Hence, many desire to perform these jobs. But the truth is, solving crimes and crime scene investigation as a whole is a very complicated job that requires both theory and practical application.
As the name implies, crime scene investigation requires you to observe, gather evidence, and analyze any information you can get at the crime scene. You will then use those data to hypothesize what took place on the crime scene, what caused the death of a victim, what method of attack is used, and the like. Presence of evidence that would help point to the identity of the suspect must also be gathered. Although this process appears to be quite simple, it is such a complex job that even learned crime scene investigators require years of working experience before they are able to develop skills needed to become better at this job.
There are multiple ways in which you can study, examine, and analyze evidential items that can help boost your crime analysis. However, all of these methods are grounded at a few basic protocol followed when processing a crime.
Scene Processing
This is the initial and most crucial aspect of crime scene investigation. Several methods and skills are involved in this step of your crime scene investigation. Processing the scene of the crime involves the interview process with eyewitness for potential information needed in solving the crime, taking photographic evidence of the crime scene and the victim’s body in relation to the crime scene, more intense evidence search, sketching the crime scene, and a few other photographic evidence that could help solve the crime puzzle.
This is the step that determines the success of your succeeding criminal investigation efforts because it involves the collection and documentation of evidence for future reference. One other factor that makes the scene processing a vital aspect of crime scene investigation is that you cannot re-create a crime scene once you have failed to gather all the information you need for further crime analysis.
Evidence Knowledge and Interpretation of Evidence
What will you do with the evidence if you lack the knowledge to interpret and analyze them? Proper methods of analyzing and handling evidences is crucial in an effective crime scene investigation. Therefore, it is a strong suit that will help keep the crime investigation going. Other evidence need to be further studied at criminal laboratories either to see if there are any fingerprints, or to see samples of blood or other substances. There have been several instances in the past wherein the DNA of the criminal is found on the evidences gathered at the crime scene that led to their arrest.
Criminal Case Processing
The ability to scan crime scenes for evidence, interpreting and analyzing them to find conclusion for a given crime is not a job suited for everyone. It requires specialized skills and knowledge, especially in terms of the technical aspects of the job such as analysis of blood samples, fingerprints, blood patterns, and other tricky part of the investigation.
Once evidence have been examined, you will then put this side by side with any testimony you have gathered from witnesses. The objective is to have a mental recreation of the events during a crime. During the recreation, investigators can factor in some possible angles of motivation for the crime that would help trace the suspect.

Crime Scene Investigation

What is Crime Scene Investigation?

Crime scene investigation jobs have been popularized by several hit crime shows on TV. Hence, many desire to perform these jobs. But the truth is, solving crimes and crime scene investigation as a whole is a very complicated job that requires both theory and practical application.

As the name implies, crime scene investigation requires you to observe, gather evidence, and analyze any information you can get at the crime scene. You will then use those data to hypothesize what took place on the crime scene, what caused the death of a victim, what method of attack is used, and the like. Presence of evidence that would help point to the identity of the suspect must also be gathered. Although this process appears to be quite simple, it is such a complex job that even learned crime scene investigators require years of working experience before they are able to develop skills needed to become better at this job.

There are multiple ways in which you can study, examine, and analyze evidential items that can help boost your crime analysis. However, all of these methods are grounded at a few basic protocol followed when processing a crime.

Scene Processing

This is the initial and most crucial aspect of crime scene investigation. Several methods and skills are involved in this step of your crime scene investigation. Processing the scene of the crime involves the interview process with eyewitness for potential information needed in solving the crime, taking photographic evidence of the crime scene and the victim’s body in relation to the crime scene, more intense evidence search, sketching the crime scene, and a few other photographic evidence that could help solve the crime puzzle.

This is the step that determines the success of your succeeding criminal investigation efforts because it involves the collection and documentation of evidence for future reference. One other factor that makes the scene processing a vital aspect of crime scene investigation is that you cannot re-create a crime scene once you have failed to gather all the information you need for further crime analysis.

Evidence Knowledge and Interpretation of Evidence

What will you do with the evidence if you lack the knowledge to interpret and analyze them? Proper methods of analyzing and handling evidences is crucial in an effective crime scene investigation. Therefore, it is a strong suit that will help keep the crime investigation going. Other evidence need to be further studied at criminal laboratories either to see if there are any fingerprints, or to see samples of blood or other substances. There have been several instances in the past wherein the DNA of the criminal is found on the evidences gathered at the crime scene that led to their arrest.

Criminal Case Processing

The ability to scan crime scenes for evidence, interpreting and analyzing them to find conclusion for a given crime is not a job suited for everyone. It requires specialized skills and knowledge, especially in terms of the technical aspects of the job such as analysis of blood samples, fingerprints, blood patterns, and other tricky part of the investigation.

Once evidence have been examined, you will then put this side by side with any testimony you have gathered from witnesses. The objective is to have a mental recreation of the events during a crime. During the recreation, investigators can factor in some possible angles of motivation for the crime that would help trace the suspect.

Disorganized crime scenes exhibit the following characteristics:
contain lots of evidence
exhibit a frenzied attack
involve single or clustered scenes
indicate the victim was not a stranger
indicate spontaneous attack
assault and disposal site of the body of the same
contain weapon of opportunity
postmortem sexual activity
include symbolic positioning of the body
The disorganized crime scene corresponds to the disorganized offender:
below average intelligence
socially immature
poor work history
sexually incompetent
anxious and confused

Disorganized crime scenes exhibit the following characteristics:

  • contain lots of evidence
  • exhibit a frenzied attack
  • involve single or clustered scenes
  • indicate the victim was not a stranger
  • indicate spontaneous attack
  • assault and disposal site of the body of the same
  • contain weapon of opportunity
  • postmortem sexual activity
  • include symbolic positioning of the body

The disorganized crime scene corresponds to the disorganized offender:

  • below average intelligence
  • socially immature
  • poor work history
  • sexually incompetent
  • anxious and confused
Crime Scene Clean Up
Crime-scene clean-up is a niche market within the cleaning industry. It’s called CTS Decon — crime and trauma scene decontamination — and it involves cleaning up dangerous material. This could mean the biologically contaminated scene of a violent death (homicide, suicide or accidental) or the chemically contaminated scene of a methamphetamine lab or anthrax-exposure site. Crime-scene cleaners come in and restore the scene to its pre-incident state.
When a violent death occurs in someone’s home, the family typically doesn’t move out of the house. The c­leaners’ job is to remove any sign of what happened and any biohazards that result from such an incident. Federal regulations deem all bodily fluids to be biohazards, so any blood or tissue at a crime scene is considered a potential source of infection. You need special knowledge to safely handle biohazardous material and to know what to look for at the scene — for instance, if there’s a thumbnail-size bloodstain on the carpet, there’s a good chance that there’s a 2-foot-diameter bloodstain on the floorboards underneath it. You can’t just clean the carpet and call it a day. You also need permits to transport and dispose of biohazardous waste. Companies that clean up crime scenes have all of the necessary permits, training and, perhaps most important, willingness to handle material that would send most of us running out the door to throw up in the bushes.

Crime Scene Clean Up

Crime-scene clean-up is a niche market within the cleaning industry. It’s called CTS Decon — crime and trauma scene decontamination — and it involves cleaning up dangerous material. This could mean the biologically contaminated scene of a violent death (homicide, suicide or accidental) or the chemically contaminated scene of a methamphetamine lab or anthrax-exposure site. Crime-scene cleaners come in and restore the scene to its pre-incident state.

When a violent death occurs in someone’s home, the family typically doesn’t move out of the house. The c­leaners’ job is to remove any sign of what happened and any biohazards that result from such an incident. Federal regulations deem all bodily fluids to be biohazards, so any blood or tissue at a crime scene is considered a potential source of infection. You need special knowledge to safely handle biohazardous material and to know what to look for at the scene — for instance, if there’s a thumbnail-size bloodstain on the carpet, there’s a good chance that there’s a 2-foot-diameter bloodstain on the floorboards underneath it. You can’t just clean the carpet and call it a day. You also need permits to transport and dispose of biohazardous waste. Companies that clean up crime scenes have all of the necessary permits, training and, perhaps most important, willingness to handle material that would send most of us running out the door to throw up in the bushes.

Apr 3
Crime Scene Staging
When investigators approach a crime scene, they should look for behavioral “clues” left by the offender.  This is when investigators attempt to find answers to several critical questions.  How did the encounter between the offender and victim occur? Did the offender blitz (ambush) the victim, or did he use verbal means (the con) to capture her?  Did the offender use ligatures to control the victim?  What was the sequence of events?  Was the victim sexually assaulted before or after death? When did the mutilation take place—before or after death?  Did the offender place any item at the crime scene or remove something from the crime scene? 
 As investigators analyze crime scenes, facts may arise that baffle them.  These details may contain peculiarities that serve no apparent purpose in the perpetration of the crime and obscure the underlying motive of the crime.  This confusion may be the result of a crime scene behavior called staging.  Staging occurs when someone purposely alters the crime scene prior to the arrival of the police. 
Reasons for Staging
Principally, staging takes place for two reasons—to direct the investigation away from the most logical suspect or to protect the victim or victim’s family.  It is the offender who attempts to redirect the investigation.  This offender does not just happen to come upon a victim, but is someone who almost always has some kind of association or relationship with the victim.  This person, when in contact with law enforcement, will attempt to steer the investigation away from himself, usually by being overly cooperative or extremely distraught.  Therefore, investigators should never eliminate a suspect who displays such distinctive behavior. 
 The second reason for staging, to protect the victim or the victim’s family, occurs for the most part in rape-murder crimes or autoerotic fatalities.  This type of staging is performed by the family member or person who finds the body.  Since perpetrators of such crimes leave their victims in degrading positions, those who find the bodies attempt to restore some dignity to the victim.  For example, a husband may redress or cover his wife’s body, or in the case of an autoerotic fatality, a wife may cut the noose or the device suspending the body of her husband.  Basically, these people are trying to prevent future shock that may be brought about by the position, dress, or condition of the victim.  In addition, they will often stage an autoerotic fatality to look like a suicide, perhaps even writing a suicide note.  They may even go so far as to the make it appear to be a homicide.
 For both types of crime scene investigations, rape-murders and autoerotic fatalities, investigators need to obtain an accurate description of the body’s condition when found and to determine exactly what the person who found the body did to alter the crime scene.  Scrutiny of forensic findings, crime scene dynamics, and victimology will probably reveal the true circumstances surrounding the deaths. 
Finally, at some crime scenes, investigators must discern if the scene is truly disorganized or if the offender staged it to appear careless and haphazard.  This determination not only helps to direct the analysis to the underlying motive but also helps to shape the offender profile.  However, recognition of staging, especially with a shrewd offender, can be difficult. Investigators must examine all factors of the crime if they suspect it has been staged.  This is when forensics, victimology, and minute crime scene details become critical to determine if staging occurred.

Crime Scene Staging

When investigators approach a crime scene, they should look for behavioral “clues” left by the offender.  This is when investigators attempt to find answers to several critical questions.  How did the encounter between the offender and victim occur? Did the offender blitz (ambush) the victim, or did he use verbal means (the con) to capture her?  Did the offender use ligatures to control the victim?  What was the sequence of events?  Was the victim sexually assaulted before or after death? When did the mutilation take place—before or after death?  Did the offender place any item at the crime scene or remove something from the crime scene? 

 As investigators analyze crime scenes, facts may arise that baffle them.  These details may contain peculiarities that serve no apparent purpose in the perpetration of the crime and obscure the underlying motive of the crime.  This confusion may be the result of a crime scene behavior called staging.  Staging occurs when someone purposely alters the crime scene prior to the arrival of the police. 

Reasons for Staging

Principally, staging takes place for two reasons—to direct the investigation away from the most logical suspect or to protect the victim or victim’s family.  It is the offender who attempts to redirect the investigation.  This offender does not just happen to come upon a victim, but is someone who almost always has some kind of association or relationship with the victim.  This person, when in contact with law enforcement, will attempt to steer the investigation away from himself, usually by being overly cooperative or extremely distraught.  Therefore, investigators should never eliminate a suspect who displays such distinctive behavior. 

 The second reason for staging, to protect the victim or the victim’s family, occurs for the most part in rape-murder crimes or autoerotic fatalities.  This type of staging is performed by the family member or person who finds the body.  Since perpetrators of such crimes leave their victims in degrading positions, those who find the bodies attempt to restore some dignity to the victim.  For example, a husband may redress or cover his wife’s body, or in the case of an autoerotic fatality, a wife may cut the noose or the device suspending the body of her husband.  Basically, these people are trying to prevent future shock that may be brought about by the position, dress, or condition of the victim.  In addition, they will often stage an autoerotic fatality to look like a suicide, perhaps even writing a suicide note.  They may even go so far as to the make it appear to be a homicide.

 For both types of crime scene investigations, rape-murders and autoerotic fatalities, investigators need to obtain an accurate description of the body’s condition when found and to determine exactly what the person who found the body did to alter the crime scene.  Scrutiny of forensic findings, crime scene dynamics, and victimology will probably reveal the true circumstances surrounding the deaths. 

Finally, at some crime scenes, investigators must discern if the scene is truly disorganized or if the offender staged it to appear careless and haphazard.  This determination not only helps to direct the analysis to the underlying motive but also helps to shape the offender profile.  However, recognition of staging, especially with a shrewd offender, can be difficult. Investigators must examine all factors of the crime if they suspect it has been staged.  This is when forensics, victimology, and minute crime scene details become critical to determine if staging occurred.

Apr 2
Margaret Bowman’s bed at the Chi Omega Sorority House, after Ted Bundy’s attack

Margaret Bowman’s bed at the Chi Omega Sorority House, after Ted Bundy’s attack

On February 21, 1974, Ted Bundy attacked Lynda Healy while she was sleeping, bludgeoning her in her bed, and abducted her. Only her skull and mandible were found at Taylor Mountain site (one of Bundy’s favorite spots).

On February 21, 1974, Ted Bundy attacked Lynda Healy while she was sleeping, bludgeoning her in her bed, and abducted her. Only her skull and mandible were found at Taylor Mountain site (one of Bundy’s favorite spots).

The Crime Scene 
Police are usually the first to arrive at the scene - if the perpetrator is still there they arrest him, and if an ambulance is needed they call one.They may collect evidence.
Crime scene investigators will arrive to collect evidence, the District Attorney may go to the scene, and a medical examiner/coroner will be there if necessary. Detective will also be called to the scene. Any specialists needed will be called.
Crime Scene Guidelines - Procedure Search Operations of a Crime Scene
1. Preparation to move into scene, which officer is going where.
approach the scene
secure and protect all surrounding area
2. Initiate Preliminary Survey of scene
Videotape the scene for the exact placement of all evidence.
Photograph Scene, all evidence, suspects, as well as the room
3. Conduct Detailed Search and Collect Physical Evidence
4. Prepare Narrative Description, use evidence to come up with a potential timeline of what happened
5. Make a rough sketch of the scene.
always set the map towards the north, measure the distance from a corner of the room to evidence and then measure the same piece of evidence to another corner to triangulate that piece of evidence
6. Interview witnesses, obtain as much information as the warrant allows. Create possible scenarios to what happened, if possible review footage taken by security cameras or review any other recording devices
7. Conduct final survey.
8. Release crime scene. 

The Crime Scene 

Police are usually the first to arrive at the scene - if the perpetrator is still there they arrest him, and if an ambulance is needed they call one.They may collect evidence.

Crime scene investigators will arrive to collect evidence, the District Attorney may go to the scene, and a medical examiner/coroner will be there if necessary. Detective will also be called to the scene. Any specialists needed will be called.

Crime Scene Guidelines - Procedure Search Operations of a Crime Scene

1. Preparation to move into scene, which officer is going where.

  • approach the scene
  • secure and protect all surrounding area

2. Initiate Preliminary Survey of scene

  • Videotape the scene for the exact placement of all evidence.
  • Photograph Scene, all evidence, suspects, as well as the room

3. Conduct Detailed Search and Collect Physical Evidence

4. Prepare Narrative Description, use evidence to come up with a potential timeline of what happened

5. Make a rough sketch of the scene.

  • always set the map towards the north, measure the distance from a corner of the room to evidence and then measure the same piece of evidence to another corner to triangulate that piece of evidence

6. Interview witnesses, obtain as much information as the warrant allows. Create possible scenarios to what happened, if possible review footage taken by security cameras or review any other recording devices

7. Conduct final survey.

8. Release crime scene. 

Forensic Analysis of Body Fluids
A number of tests are used to analyze blood, semen, saliva and other bodily fluids:
Semen: To test a sample to see whether it contains semen, technicians use acid phosphatase,  an enzyme found in semen. If the test turns purple within a minute,  it’s positive for semen. To confirm the results, technicians look at  stained slides of the sample under a microscope. The stain colors the  heads of the sperm red and the tails green (which is why the test is  referred to as the “Christmas tree stain”).
Blood: the Kastle-Meyer test uses a substance called phenolphthalein, which is normally colorless, but turns pink in the presence of blood. Another test for blood is luminal, which is sprayed over a room to detect even the tiniest droplets of blood.
Saliva: The phadebas amylase test is used to detect a-amylase, an enzyme in human saliva. If amylase is present, a blue dye will be released.

Forensic Analysis of Body Fluids

A number of tests are used to analyze blood, semen, saliva and other bodily fluids:

  • Semen: To test a sample to see whether it contains semen, technicians use acid phosphatase, an enzyme found in semen. If the test turns purple within a minute, it’s positive for semen. To confirm the results, technicians look at stained slides of the sample under a microscope. The stain colors the heads of the sperm red and the tails green (which is why the test is referred to as the “Christmas tree stain”).
  • Blood: the Kastle-Meyer test uses a substance called phenolphthalein, which is normally colorless, but turns pink in the presence of blood. Another test for blood is luminal, which is sprayed over a room to detect even the tiniest droplets of blood.
  • Saliva: The phadebas amylase test is used to detect a-amylase, an enzyme in human saliva. If amylase is present, a blue dye will be released.
Fiber evidence
Infrared spectrometry/spectroscopy identifies substances by passing infrared radiation through them and then detecting how much of the radiation they absorb. It can identify the structure and chemical components of various substances like soil, paint or fibers. With this technique, forensic technicians can match fibers found on a victim’s body to those in a piece of clothing or furniture.
Fiber evidence was crucial in the the case against Wayne Williams, Atlanta Child Murderer, and Steven Pennell, the I-40 Killer. 

Fiber evidence

Infrared spectrometry/spectroscopy identifies substances by passing infrared radiation through them and then detecting how much of the radiation they absorb. It can identify the structure and chemical components of various substances like soil, paint or fibers. With this technique, forensic technicians can match fibers found on a victim’s body to those in a piece of clothing or furniture.

Fiber evidence was crucial in the the case against Wayne Williams, Atlanta Child Murderer, and Steven Pennell, the I-40 Killer.