What is Criminal Investigation?

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

What is Criminal Investigation?

A criminal investigation is the process of discovering, collecting, preparing, identifying and presenting evidence to determine what happened and echo is responsible (Schmallegar, 2009)

Du Preez (1991:2) further describes crime investigation as a systematic and planned information collection process. It consists of observation and/or inquiry conducted during different phases in order to collect information concerning an alleged crime or incident.

Smit, Minnaar and Schneitler (2004:27) believe that criminal investigation is a reconstructive method that uses deductive analysis created on specific sections of evidence to verify proof that a suspect is guilty of an offence. In this regard Goss (2004:5) discusses that most investigations strive for to determine whether an offence has been committed. Legally attain sufficient evidence and testimony to identify the guilty person, discover and arrest the accused. And recover stolen belongings and present the best achievable case to the prosecutor.

Amongst the several occupations performed by investigators are providing emergency assistance, secure the crime section, take pictures of the crime scene, videotaping and sketching, taking records and writing transcripts and reports, searching for, gaining and processing physical evidence, attaining evidence from witnesses and suspects, discovering suspects, controlling raids, surveillances, observations and undercover assignments and testifying in court.

Emergencies are handled first, and then the crime scene is secured. Every suspect at the scene must be detained, interrogated and then either released or arrested, depending on the situations. If a suspect has lately left the scene, a specific explanation of the suspect, any means of transportation, direction of travel and any items taken should be obtained and dispatched to the headquarters immediately.

After emergencies are dealt with, the first and most important function is to protect the crime scene and evidence. All required measures to protect the crime scene should be held, including securing, roping, barring and guarding till the preliminary investigation is concluded. Once the scene is secured, the first investigation is conducted which includes photographing and videotaping, sketching and measuring the scene, searching for evidence, categorizing, collecting, examining and deal with physical evidence, questioning victims, witnesses and suspects and recording all statements and observations in notes.

The ultimate responsibility for resolving crimes lies with all police staffs. It requisite is cooperative and coordinated. Cooperation and coordination of efforts are also required outside the police department. Investigators must inter relate not only with uniformed patrol officers but also with dispatchers, the prosecutor’s employees, the defense counsel, medical doctors, the coroner or medical examiner, laboratories and people, including the injured party. Criminal investigation is indeed a mutual effort.

Investigating Crime


Homicide investigations are challenging and frequently require all investigative techniques and skills. A basic requirement is to prove whether death was caused by a criminal act. The investigation of death focuses primarily on the cause of death aand also on the underlying actions of the person who caused the death. The four basic types of death are caused by natural causes, accidental death, suicide and homicide. Although technically you are concerned only with homicide, you frequently do not know at the start of an investigation what type of death has occurred; therefore any of the four types of death may require investigation. Whether the concern is one of criminal or civil importance depends heavily on the evidence that verify aggravation or mitigation of the acts. In both occurrences the use of forensic evidence ascertains the cause of death and also the method or manner.

"Homicide" is a common term for the causing of somebody's death by another. Not all homicides are taken into consideration as criminal (felonious). Whereas, the expression is usually inaccurately used to explain certain types of illegal killings, such as murder and manslaughter. Homicides are in general classified under two vast categories: nonfelonious and felonious.

Generally many state criminal codes reflect nonfelonious homicides to be either justifiable, the intentional, really accidental killing of another individual and/or indefensible in nature – killing another person with the authorization of the law. Explicable killings usually involve elements of fault, but the acts are not adequate to be judged as criminal. Case in point of excusable homicides involve unintentional shootings and car collisions that do not include gross neglect or the intent to injure.

Justified homicides differ from defensible homicides in involving intent, whereas also being reflected legal by society. Instances involve state-ordered executions, firing of criminal suspects who act for clear and sudden threats to life, and the killing of opponent soldiers in wars.http://salempress.com/store/images/parts/clear.gif On the contrary, felonious homicides are at all times considered illegal and are frequently generically mentioned to as criminal homicides. Various states broadly split criminal homicides into manslaughter and murder, but several jurisdictions prefer to categorize illegal killings by numerical degrees, such as murder in the first or second degree. Different to what may be common belief, above all criminal homicides are not, by classification, "murders." Many definitions of murder in lawful codes need the component of premeditation, which is regularly termed a purpose to malice or kill aforethought.http://salempress.com/store/images/parts/clear.gif Premeditation is allowing for, preparation or organizing for an act, no problem how briefly, before causing it. Premeditatin is the component of first degree murder that arrays it separately from all other categories. Criminal homicides that absence premeditation are usually known as manslaughter. As murder, manslaughter is constantly illegal. It varies in lacking premeditated intent. Furthermost criminal homicides committed in the United States fall in the categorization of manslaughter, not premeditated murder. This may be established by statements from witness of from the victim before death, from evidence at the crime scene or through a review of the suspect’s criminal history and past statements.

The most challenging and difficulty in homicide investigations is to establish whether it is a homicide rather than a suicide or an accidental or natural death, recognizing the victim and establishing the reason and time of death.


Investigative Approach

The first priority in a preliminary homicide investigation is to provide emergency aid to the victim if he or she is however alive or to conclude that death has occurred, provided the suspect is not at the scene. Signs of death contain lack of breathing, absence of heartbeat, shortage of flushing of the fingernail bed once pressure is applied and at that time released and failure of the eyelids to close once being gently lifted. Later priority matters are accomplished, the emphasis of the homicide investigation is to find the victim, determine the time of death and reason of death and the technique used to produce it and to develop a suspect.

Intent is not sufficient to gain a conviction. Individuals sometimes have a reason and an occasion but there must be proof that they together committed the crime and that their action was the reason of death. In the law court, the prosecuting group must be able to verify that the accuser’s action were a considerable factor in the death of the victim and that the deceased would be alive but for these acts. Consequently, it is the intention of the homicide investigator to discover evidence of these facts.

Sequentially to do this efficiently, there are some things that must be completed. The first officers to be notified must hurry to the crime scene so that all presented evidence is not interfered. The whole lot in and around the area requires to be cordoned off and measured as evidence. At this moment, reports are collected from witnesses, if there are any and any suspects are to be in custody. Homicide victims are identified by their relatives, friends or acquaintances, by personal effects, fingerprints, DNA analysis, skeletal studies including teeth, clothing and laundry marks, or through missing-persons files.

Once the scene has been safeguarded it is time for the homicide investigation squad to arrive. These officers must manuscript all evidence at the scene via photos and videotaping. All must be cautiously analyzed and the investigators must plods so as not to contaminate the scene or disrupt such fingerprints. Their duties is to identify the victim and establish a time and case of death. The majority of homicides are caused by someone who is recognized by the victim. Determining the case of death is tremendously important in any homicide investigation, as it commonly provides the investigators with valued evidence. Common factors used to evaluate time of death, appearance of the eyes, rigor mortis, body temperature, stomach substances, postmortem lividity, phase of decomposition and evidence signifying a change in the victim’s common routine. Body temperature falls 2 to 3 degrees in the beginning hour after death and 1 to 1 ½ degrees for each following hour up to 18 hours. Rigor mortis performs in the head 5 to 6 hours after death, in the upper body later in about 18 hours. Later around 36 hours, rigor mortis generally vanishes in the same structure as it appeared. Any weapon tightly clutched in the victim’s hand as the result of cadaveric spasm indicated suicide rather than murder. Postmortem, lividity starts ½ to 3 hours after death and is firm in the capillaries in 4 to 5 hours. Extreme lividity happens within 10 to 12 hours. The position of lividity can specify whether a body was repositioned after death. A part restraint of the pupil happens in about 7 hours. In 12 hours the cornea looks cloudy. The investigator must decide when and what the victim last ate. If any vomit is existent, it should be kept as evidence and succumbed for examination. A dead figure generally sinks in water and stays immersed for 8 to 10 days in warm water or 2 to 3 weeks in cold water. It then appears to the surfaces if not restricted. The surface skin loosens in 5 to 6 days, and the nails split up in 2 to 3 weeks. The direction of entry of a bullet or knifes provides investigators a clear representation concerning the intent of the suspect.

The victim’s background can also provide evidence about whether the death was an unintentional, a suicide or homicide. This background and the evidence on the victim’s body often lead to a suspect. Physical evidence in a homicide consists of a body, blood, hairs, fibers and a weapon. An autopsy of the victim normally uncovers many truths regarding the case.

Evidence in Investigation and Contribution to the Justice System

Investigative notes and reports are critical parts of a criminal investigation. Notes are a permanent written record of the facts of a case to be used in further investigating and in prosecuting the case. Start to take notes as soon as possible after receiving an initial call to respond, and continue recording information as it is received throughout the investigation. Record all relevant information concerning the crime, the crime scene and the investigation, including information that helps answer the questions, Who, What, When, How and Why. Make notes complete, accurate, specific, factual, clear, well organized and legible. Original notes are legally admissible in court and may be used to testify.

Photography, is one of the investigative techniques to be used at a crime scene, helps to establish that a crime was committed and to trace the occurrence of the crime. Photos and videotapes replicate the crime scene in depth for presentation to the defense, prosecution, judge, witnesses, and jury in court. They are utilized in investigation, prosecution and police training. Photography is important in criminal investigation because it can immediately preserve evidence, accurately present the crime scene and evidence, create interest and increase attention to testimony.

In addition to photographs, crime scene sketches are often used. The steps involved in sketching include observing and planning, measuring distances and outlining the general area, locating, measuring and recording objects, evidence within the outline, note taking, identifying the scene an reassessing the sketch. A sketch helps in interviewing and interrogating individuals, preparing the investigative report and presenting the case in court. Photographs, sketches and written notes among others are often needed to provide clear picture of the scene.

To be of value, evidence must be legally and properly seized and processed. Processing physical evidence includes discovering, recognizing and examining it, collecting, recording and identifying it, packaging, conveying and storing it, exhibiting it in court and disposing of it when the case is closed. The importance of physical evidence depends on its ability to establish that a crime was committed as well as how, when and by whom. Frequently examined physical evidence includes fingerprints, voiceprints, DNA, body fluids, hairs and fibres, tools and tool marks, firearms, and many other types of evidence.

All evidence must be properly packaged so as to keep it in substantially the same condition in which it was found. The best evidence rule stipulates that the original evidence is to be presented in court whenever possible.

To be admissible as evidence in court, be able to

  1. Recognize the evidence as that originate at the crime scene,
  2. Explain precisely where it was found,
  3. Determine its custody as of discovery to the present, and
  4. Voluntarily describe any deviations that have occurred in the evidence.


There are three forms of evidence, real objects, documents and testimony. There are no specific ways to investigate or to find a crime. It is based on a mix of attributes of an investigator, who needs to use his common sense, judgment, intelligence and skill. Most importantly the investigator has to rely on his inside feeling or intuitions. He/She must investigate keeping in mind his experience, study of cases and use of his expertise. Every scenario of a crime will be different, and accordingly he/she will have to change his methods of observation of the criminal's behaviour. The basic types of investigations that are done by officers on a daily routine bases are the investigation of incidents that were due to violations like robbery, rape, illegal weapons and accidents on roads. Others include personnel investigations that are to observe backgrounds, daily routines of people and their overall living. Therefore, it is a huge responsibility on the part of an investigator to confer his efforts towards criminal investigation in the best possible way. Failure on the part of the investigation leads to a number of negative consequences such as individuals who commit a felony and escape trial are encouraged to perform illegal acts in the future.


Becker, R. F. (2009). Criminal Investigation. United States: Jones and Bartlett Publishers.

Preez, P. D. (1991). Science of Mind:The Quest of Psychological Reality. USA: Elsevier Science & Technology Books.

Schmalleger, F. J. (2009). Criminal Justice : A Brief Introduction. USA: Prentice Hall PTR.

Smit, M. a. (2012). The Use of Physical Surveillance in Forensic Investigation. University of South Africa: Magister Technologiae.