What are the first steps of a homicide investigation? When we think of CSI or forensic science, the first thing that comes to mind is a bloody crime scene or murderous serial killers, but homicides may only make up an extremely small percentage of the crimes a CSI will investigate. Thankfully, murder is a rare occurrence in many jurisdictions, so when it
does occur, it draws huge attention and everyone wants to get involved in the case. Homicide investigations rely on a large amount of teamwork and draw upon many sources of information, and forensic evidence is only one component of it. Let’s take a brief look at the 5 defining characteristics of a homicide and how they are essential in helping investigators understand their crime and apprehend their criminal. These characteristics were developed and defined in the FBI’s Crime Classification Manual, Second Edition, whose goal was to standardize terminology, facilitate communication within the criminal justice field, educate the criminal justice system and public about the types of crimes being committed, and develop a database for investigative research.
What makes homicides unique from property and non-violent crimes is the fact that there is a victim. The victim is very often the most important investigative tool, since a lot of information can be revealed about the case from studying the victim. If investigators can answer the question why the victim was targeted, then they are often lead to the motive and potentially their offender. Areas of the victim’s lifestyle, habits, relationships, employment, personality, leisure activities, alcohol/drug abuse, dating habits, etc. are excellent sources of information about what increased the victim’s risk.
2. Crime Scene Indicators
The location, environment, and time of day may present significant clues as to the nature of the perpetrator and the amount of risk he is willing to take and shed light on the motive of the criminal. It is also possible for there to be several crime scenes as well, such as if the victim was transported at some point during the crime, and that may tell investigators how organized the criminal is. The disposition of the body at the crime scene, if it was concealed, displayed, or positioned may also tell investigators a lot about the criminal and if there was a message sent by the murder. Furthermore, items are often left at the scene, such as a weapon, or removed from the scene, such as a souvenir, which can narrow down the type of criminal, and restraints or other tools of the crime left at the scene can potentially paint a better picture of the crime.
This is the purposeful alteration of the crime scene, meant to mislead investigators. Inconsistencies in the crime scene often uncover staging attempts.
4. Forensic Findings
The value of physical evidence at the crime scene is well known and can be crucial to any homicide investigation. The cause of death, types of trauma, indications of sexual assault, toxicology reports, and hair/DNA/fingerprint/etc. analysis can all lead to apprehending the criminal.
5. Investigative Considerations
These considerations are usually taken once the homicide has been classified, and may include search warrants, locating and interviewing witnesses, and documenting the crime scene.
By using these defining characteristics as a starting point, investigators are usually able to gather a lot of information that will help them in the case. They also generate profiles of criminals to help them determine motive and opportunity. Finally, the information that they gather may help investigators link different crimes based on similar MO’s or criminal signatures, and may be the key to breaking other cases.