Criminal Law

By Peter Woodhouse


Do you recognise this person? 

The danger of using Facebook as a means of identifying suspects.

Apparently, 2.7 billion people use Facebook, WhatsApp, Instagram or Messenger each month and more than 2.1 billion use at least one of the Facebook family every day.

With that sort of exposure, there’s little wonder that the investigative authorities have jumped on the social media bandwagon.

ACT Policing often turns to the public for assistance in identifying suspects by sharing photographs or CCTV footage on their Facebook page and through media release.  Often each post receives hundreds of ‘likes’ and ‘shares’.  The exponential exposure created when the post is seen by the friends and followers of the likers or sharers would be in the tens of thousands.

Whilst that tool may be useful in gathering some suggestions of who a particular perpetrator might be, there is a bigger risk of undermining the criminal justice system by adversely effecting the evidence gathering process and creating a fundamental unfairness in the identification of a suspect due to memory contamination.

Memories are susceptible to errors and biases.  An eyewitness’ memory can be easily contaminated leading them to make serious, but often understandable and even predictable errors when attempting to identify a perpetrator of a crime.  There is an abundance of psychological research on problems with identification evidence and the subconscious influence that having seen a person’s photograph or likeness previously has on reliable identification evidence.

People are often surprised to learn that police actually conduct identification parades or ‘line-ups’.  Whilst they are relatively rare, they are quite effective and when done fairly, the results often carry a lot of weight.  Believe it or not, identification parades are one aspect of the criminal law that is quite like what they depict in the movies – think Keyser Soze in The Usual Suspects.

The wide circulation of a photo or CCTV footage of a person the police think may have done something has the potential to render that procedure unfair and utterly useless.

Take this example:

Peter is present at a shopping centre when a purse snatching takes place.  A witness, Susanne, suggests to police that somebody fitting Peter’s general description (tall, dark and handsome) was involved in the snatch.  CCTV footage of Peter calmly walking out of the shopping centre is shared on Facebook and viewed by thousands of people in the local area, including Susanne.  An identification parade is held and Susanne picks Peter out of the line-up.  That identification could either be from Susanne genuinely thinking Peter was the one who snatched the bag OR due to Susanne’s memory of the person she saw on Facebook, who may or may not have been the perpetrator.  There is no way of knowing and Susanne’s identification of Peter is wholly unreliable.

If it hasn’t already done so, it is only a matter of time before this type of social media exposure of an alleged suspect’s image has a significant and irrecoverable impact on the fair and proper identification of a perpetrator.  The consequences are potentially wide-ranging from rendering identification evidence inadmissible, to creating a fundamental unfairness to the accused person or even derailing an entire criminal prosecution.  It is short-sighted of the authorities to not consider this when they call on the public to assist in the first place.