Why Investigations Matter

Criminal investigations serve as the gateway to the entire justice system. Without solving a crime and identifying a suspect, further processes, such as prosecution, trial, and sentencing, cannot occur. To understand the outcomes of policing and justice, it is necessary to understand investigations. 

INVESTIGATION PHASES

There are three core phases in most criminal investigations:

  1. Evidence Phase – Gathering, evaluating, and analyzing physical and testimonial evidence.
  2. Suspect Phase – Generating suspects, prioritizing them, and conducting assessments (e.g., checking alibis, interviewing witnesses).
  3. Offender Phase – Proving who committed the crime, typically through a witness, a confession, or physical evidence.

These phases often overlap and are not always followed in order. A suspect, for example, may be identified before all the evidence is collected. 

By applying structure and vigilance to the investigative process, detectives can reduce errors and increase the chances of solving crimes correctly. 

Quick References

Expand FAQ List

  • How Criminal Investigative Failures Occur

    • It includes anything that helps establish what happened, crime scene photos, witness statements, lab reports, or forensic samples. Evidence must be considered holistically, a principle referred to as SRIP (Strength, Reliability, Independence, Pattern). 

      • Strength refers to how much the evidence supports a conclusion (e.g., guilt or innocence). 
      • Reliability means how accurate or trustworthy the evidence is. 
      • Independence is whether the evidence provides new information. 
      • Patterns are the overall picture formed when evidence is considered together. 

       

    • Investigations fail in three ways: 

      • Ignored crimes – When crimes are not recognized or recorded correctly. 
      • Unsolved crimes – When a case that could have been solved is mishandled. 
      • Wrongful convictions – When the wrong person is convicted due to errors in the investigation. 

       

      • Confirmation bias – Interpreting evidence to fit a theory rather than letting the evidence guide the theory. 
      • Tunnel vision – Focusing on one suspect too early and ignoring alternatives. 
      • Rush to judgment – Jumping to conclusions before enough information is available. 
      • Improper forensic work or witness pressure – Including unreliable confessions or lab errors. 

      Rossmo (2021) found that over 60% of investigative failures are due to personal decision-making problems, such as rushing to judgment or failing to consider alternative suspects. 

  • Preventing Criminal Investigative Failures

    • Criminal investigators are time travelers, piecing together past events from limited evidence. They require logical analysis, critical thinking, and a willingness to challenge early assumptions.  

      To prevent failure, investigators must ask: 

      • Was any evidence missed? 
      • Has it been properly analyzed? 
      • Are we interpreting this based on facts or assumptions? 

  • Questions to Consider

      • What are the location types connected to this crime or crime series? 
      • Where are these locations? Map them! 
      • What are the distances and travel times between them? 

      • When did the crimes occur (date, time, weekday)? 
      • What was the weather? 
      • How much time was there between crimes?  

      • How are the crime locations accessed? 
      • What else is in the general area? 
      • How might the offender have known of these locations? 
      • What purpose did the crime locations serve? 

      • Where is the target group (and where is it not)? 
      • How much control did the offender have over the choice of crime locations? 
      • Has displacement (in space or time) occurred?  

      • What hunting method did the offender use? 
      • Why these sites and not others? 
      • What was the offender's likely transportation?