Solving criminal cases through crowd-sourcing

I started writing this post a few days ago after reading this article. It looked extremely interesting. The main idea is that in the Boston marathon there were thousands of mobile phones taking pictures and videos. The total duration and number of all videos and pictures shot could be stunning. This could be equivalent to thousands of witnesses testifying with absolute accuracy what they saw. The author was wondering whether crowd-sourcing could become a tool to crime solving. She probably meant to write modern crowd-sourcing as some forms of crowd-sourcing have been in use since long time ago as we will see further below.

It was reasonable to expect that the authorities would like to collect and use all available material that could help them in their efforts to find the people responsible for the bombings. This is in fact what they tried to do. In a few days after the bombing, surveillance videos of high quality were analyzed and the authorities came up with pictures and names of suspects for the bombing. At the same time, the whole effort had already been crowd-sourced. The FBI launched a tip site for the public to contribute tips and upload media files. It has been reported that there was tremendous response from the side of the public. Efforts from other groups have also been highlighted. Reddit had launched a thread on “/r/findbostonbombers“. The Thread is no longer accessible as the bombers have already been identified.

  • Snapshot from the no longer accesible reddit thread
    Snapshot from the no longer accesible reddit thread


The Boston case is an example showing the power of modern technology and communication capabilities. In this case the authorities used thousands of tips and leads as well as high quality surveillance videos in order to identify the suspects. The help of the public was also sought in order to locate the suspects. As Mr DesLauriers (special agent in charge of the Boston Division of the FBI) said: “For more than 100 years, the FBI has relied on the public to be its eyes and ears. With the media’s help, in an instant, these images will be delivered directly into the hands of millions around the world. We know the public will play a critical role in identifying and locating them”. According to Mr DeLauriers’ words some form of crowd-sourcing has been used by the FBI for a long time now. What remains to be discussed is what form could modern crowd-sourcing assume.

Let us  first see what has changed in recent years from a technological point-of-view.

  • The new communication paradigm (Web 2.0) including real-time, interactive social media has the conversation element built-in. Large scale co-operations can be set-up in minutes.
  • Data transmission speeds have improved so much that a lot of people may upload full high definition videos they shot with the camera of their mobile phone, while still at the crime scene. There is no need to even have a computer.

What is missing is a permanent platform hosting and managing crowd-sourced crime solving cases. This platform would be something like the FBI tip-site. The effort could be backed by government and large technology companies which will provide know-how and resources.

  • Users would be able to upload their files and personal particulars or upload thir files anonymously if they wish to protect their identity.
  • The platform should also be supported by a strong traditional and social media advertising effort. A large social media audience may serve in quick advertising of the case to be solved and spark discussions that may sensitize the public on the case. It looks like if the sensitization of the public over a case is achieved, people take active role in helping the authorities. Furthermore, by reaching as many people as possible the efficiency of collecting relevant footage would be increased and the probability of finding useful witness testimonies would also be maximized. In the Boston case the FBI had footage from surveillance cameras. Such data are usually easy to collect because it is relatively easy to track the existence of cameras. What would happen if there were no surveillance camera footage available. How would the authorities collect all the audiovisual material from civilians? Well, probably the best way would be what the FBI already did. A tip site giving users the option to upload their multimedia material. However, this was a major crime involving thousands of witnesses. A lot of footage and pictures from civilians were available. This will not be the case for every crime but consider that technology and communication will keep evolving and spreading. Mobile devices will have more capabilities to record audiovisual data. I think it is not far fetched to think that the possibility of finding audiovisual material for many crime cases will keep increasing in the future.
  • Another feature of a dedicated crowd-sourced crime solving platform could be to give users the option to review material for suspicious activity if they would wish to. Imagine a case of similar social impact with the Boston Marathon bombings. Endless hours of videos would be available.  All this material would need to be reviewed by a limited number of people who would be tired of this and probably find it difficult to finish the job diligently. So what if this job was all crowd-sourced?  What if the authorities could let the worldwide Internet audience contribute to the effort. Now you may think: Are we really gonna give the job of professionally trained detectives to the public? Would this work? Well, I think that professional detectives will be the ones who will finally solve the case. But even the smallest help could be crucial. If someone argues that the users would not be interested, I would say that people play games on their PCs and recently on Facebook trying to become virtual detectives. Interrogating virtual suspects in online games!


Crowdsourced detective work
Web-detectives in action!