BlackRainbow: proactive, reactive and crime in action  

June 27, 2024



Matt Bonner, Head of Investigation Technology at BlackRainbow, explores the different types of investigations that face investigators and asks, are they really all that different? 

Investigations are a cornerstone of law enforcement and criminal justice, aimed at uncovering the truth behind criminal activities and bringing perpetrators to justice.

There are various investigative approaches, but three primary types stand out: proactive investigation, reactive investigation, and crime in action investigation.

Whilst each of them has unique characteristics, the investigative approach required might share more common ground than first thought.  

Proactive Investigation 

Proactive investigation involves law enforcement actively seeking out criminal activity before it is reported or becomes widely known.

This approach often relies on intelligence gathering, surveillance, undercover operations and the use of human intelligence sources.

Often, with a proactive investigation, the objective is to prevent crimes before they occur or catch criminals in the act. 

Methods and techniques 

  1. Surveillance: Continuous monitoring of suspects to gather evidence and understand their activities. 
  1. Undercover Operations: Officers infiltrate criminal organisations to gather critical information. 
  1. Human Intelligence: Utilising those who provide valuable information about criminal activities. 
  1. Data Analysis: Analysing patterns and trends in crime data to identify potential hotspots and suspects. 
  1. Sting Operations: Setting up scenarios to catch criminals in the act, such as posing as buyers in drug supply networks. 
  1. Complex Operations: Undercover and surveillance operations can be dangerous and require specialized training and coordination. 

Reactive investigation 

Reactive investigation is initiated in response to a reported crime. Once a crime is committed and reported, law enforcement agencies react by investigating the incident to identify the perpetrator and gather evidence for prosecution. 

Methods and Techniques 

  1. Crime Scene Investigation: Collecting and analysing physical evidence from the crime scene. 
  1. Witness Interviews: Gathering accounts from witnesses and victims to piece together the sequence of events. 
  1. Forensic Analysis: Using scientific techniques to analyse evidence such as DNA, fingerprints, and ballistic information. 
  1. Case Reviews: Reviewing similar cases for patterns that might help in solving the current case. 
  1. Suspect Interviews: Questioning suspects in relation to their suspected involvement in an offence.  

Crime in Action Investigation 

Crime in action investigation involves law enforcement responding to an ongoing crime. This type of investigation occurs in real-time as officers intervene in criminal activities as they are happening. 

Methods and Techniques 

  1. Rapid Response: Immediate deployment of officers to the scene of the crime. 
  1. Emergency Communications: Using 999 calls and other emergency communication systems to locate and respond to crimes. 
  1. Specialist Units: Likely to involve a number of different police specialisms all working together for a common purpose ie. Surveillance Teams, Firearms Teams, Negotiators etc.  
  1. Technology Use: Real-time surveillance, drones, and other technologies to monitor and assess the situation. 

Different demands 

At first glance, these different types of investigation share very little in common and the demands place on investigators leading each are unique in their own way.

One obvious difference is the impact of each case on the victims.  

In a reactive investigation, by definition, a victim has already come to some harm.

They may have had property stolen from them, they may been injured in some way or in the worst case they may have been killed and the investigation is seeking justice on behalf of a bereaved family.

The victim or their family will rightly be at the heart of the investigation and will need to be kept updated with progress. 

In a proactive investigation, the objective is usually to prevent future harm of victims (who are yet to be identified).

A proactive surveillance operation on a team of burglars, might not know where the team are likely to target, but the intention is to get into a position to act when an offence is being committed.  

Conversely, where there is a crime in action such as a kidnap, the priority might be to prevent the victim coming to any further harm.

Every effort will be made to achieve this objective and the prevention of harm will likely take priority over a successful prosecution if necessary. 

But are they really that different?…. 

A blended response 

The reality of course is that the challenges facing an investigation are not always so distinct.

An effective response is likely to require a combination of approaches to achieve a successful outcome – regardless of what success looks like.

Many reactive investigations will require a proactive response, such as during a manhunt situation where a suspect has been identified and then proactive tactics are utilised to effect an arrest.  

Equally, a Crime in Action will almost certainly require a reactive investigative approach to gather forensic or witness evidence for example.

A CCTV trawl might be required in the area of an abduction to identify any vehicles that may have been used or a search of ANPR data might be necessary to track the movements of a suspect vehicle.  

It quickly becomes apparent that the effective investigator is required to move between different phases as the need arises and is rarely dealing with one type of investigation in isolation.

Of course, the skills and experience that is required by those working in the different specialisms vary and investigators will often have their own preferences as to where they work dependant on their own particular attributes and areas of interest, but those tasked with managing the police response need to be much more omni competent.

They need to have the ability to quickly adapt their approach as a situation develops and be comfortable as they move between different response types. 

Investigation management 

In the same way that an Investigator need to be able to move between different phases of an investigation, deploying different tactics as required, the systems and process used to manage the investigation need to be equally agile.  

At its heart, regardless of the type, all investigations are conducted in the same way.  

What do I know – What is known at this time. This may be witness evidence, surveillance activity, forensic results etc.  

What do I need to know – Where are the information gaps. Who did the witness see, what is the intended target by the team of burglars, whose fingerprint is at the crime scene. 

Where will get the information I need – What activity do I need to task to fill the information gaps.  

Review – Having filled the information void, what next. What do I know, what do I need to know etc. 

This approach to conducting an investigation is suitable regardless of what is being investigated – a homicide, a suspected drug gang, a kidnap or a missing person.

The same approach can be taken.

And so, if that is the case, surely the same methods of investigation case management can also be used.

A case management system needs to be able to support the different phases of an investigation regardless of what is being investigated.  


One such system in Black Rainbow’s Nimbus. Developed by the Investigator for the Investigator, Nimbus has three distinct platforms that all work seamlessly with each other: NIMBUS Forensics a forensic case management platform; NIMBUS Intelligence a dedicated intelligence platform and NIMBUS Investigator, a powerful end to end case management system.  

After all, are they really all that different? 

This article was originally published in the July Edition of Security Journal UK. To read your FREE digital edition, click here.

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