Criminal investigation
Applied science of facts for criminal trials.
Last updated
Criminal investigation is a practical field that examines facts to support criminal trials. It encompasses activities like searching, interviewing, interrogating, collecting and preserving evidence, and using various investigative methods. Today, investigators often rely on forensic science, a set of modern scientific techniques.
This practice is ancient, with possible origins in the Code of Hammurabi, which indicated that both accuser and accused could present their own evidence. In modern times, government police forces typically handle criminal investigations, though private investigators are sometimes hired to conduct or assist with them. One early recorded professional investigator was the English constable, who around 1250 CE was noted to record matters of fact, not matters of judgment or law. On-site investigation methods are sometimes called "shoe leather."
Investigators often assess potential suspects using three indicators known as MMO: means (tools and physical ability), motive (such as financial gain or revenge), and opportunity (including being at the crime scene when it occurred; those with alibis may be ruled out). They also examine relationships between victims and possible offenders.
Investigation priority bias problems and proposed solutions
Some criminologists have observed that when certain crimes receive higher investigative priority, their demographic makeup can shift. For example, as priority for investigating terror crimes increased, the percentage of women convicted for joining and fighting for terrorist organizations rose from very low (similar to murder and rape rates) to nearly equal to men (40–50 percent in some places). These experts suggest other crimes might also change demographics if given higher priority.
They theorize that with limited budgets, investigators often rely on profiles and statistical likelihoods of certain groups being convicted, potentially ignoring complaints about people deemed less likely to commit crimes or giving their evidence lower priority. This can create a self-fulfilling prophecy where even minimal differences in crime likelihood are amplified in conviction statistics. Some criminologists see criminals who evade detection due to being profiled as unlikely offenders as a major problem. Proposed solutions include hiring more police officers.
Others note that investigating evidence is costlier than patrols, and not all crimes can be investigated. They suggest replacing psychological profiling with randomized priorities for individual suspects within similar crime types. This randomization, they argue, could expose currently unsuspected criminals to punishment and save money by eliminating forensic psychology and psychiatry profiling, freeing funds for technical evidence work and tracking hidden criminals, reducing the need to ignore complaints due to budget constraints.
Lore & Background
Criminal investigation is an applied science that examines facts to inform criminal trials. Its history is ancient, with potential roots in the Code of Hammurabi, which allowed both accuser and accused to present collected evidence. An early recorded professional investigator was the English constable; around 1250 CE, the constable’s role was to record matters of fact, not matters of judgment or law. Modern investigations are primarily conducted by government police forces, though private investigators are also commonly hired.
On-site investigative methods are nicknamed "shoe leather." A complete investigation may include searching, interviews, interrogations, evidence collection and preservation, and various methods. Contemporary investigations often employ forensic science techniques. Investigators commonly use three indicators of suspicion for potential suspects: means to commit the crime (tools and physical capabilities), motive (such as financial gain or revenge), and opportunity (including being at the scene at the time of the offence); persons with an alibi can be eliminated.
Relationships between victim and potential offenders are also established. Some criminologists note that changes in investigation priority can alter crime demographics, as seen with terror crimes where the percentage of women convicted rose from very low to nearly equal to men. They theorize that limited budgets lead investigators to rely on profiling and statistical likelihood, potentially ignoring complaints about groups considered less likely to offend. Proposed solutions include increasing police numbers or replacing psychological profiling with randomized suspect priorities within similar crime types to expose hidden criminals.
Reader's Guide
Criminal investigation serves as the foundation for criminal trials by systematically gathering and analyzing facts. Its significance lies in its long history, from ancient legal codes to modern forensic science. Investigators commonly use three indicators of suspicion—means, motive, and opportunity (MMO)—to assess potential suspects, and they establish relationships between victims and offenders. Recent discussions among criminologists highlight potential bias in investigation priority: as the priority of investigating terror crimes increased, the percentage of women convicted for such crimes rose from very low to 40–50 percent in some jurisdictions.
This has led to hypotheses that profiling and statistical likelihood may cause self-fulfilling prophecies, hiding actual crime rates. Proposed solutions include increasing police numbers or replacing profiling with randomized priorities within similar crime types, which could expose unsuspected criminals and save money for technical evidence investigation. The legacy of criminal investigation thus includes both its enduring methods and ongoing debates about fairness and effectiveness.
More in Criminal Law & Procedure
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Criminal investigation (CC BY-SA 4.0).
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced