Obtaining Data

‘“Data! data! data!” he cried impatiently. “I can’t make bricks without clay.”’
‘THE ADVENTURE OF THE COPPER BEECHES’
In his pursuit of the data vital to his professional occupation, Holmes relied on three main sources: the wealth of information stored within his brain,
clues specific to a particular case that he discovered ‘in the field’, and reference sources.
Let us start by talking about his skill as a gatherer of clues.



In an age when forensic detective work was a relatively new phenomenon, Holmes
could read a crime scene and rake it for evidence like no other. He was way ahead of his time in appreciating the use of fingerprints, footprints,
bloodstains and the like, as well as the time-sensitive nature of evidence-gathering. Here we may conjure the classic image of Holmes as he
‘whipped a tape measure and a large round magnifying glass from his pocket.’ In this respect, he often found himself battling the plods from the
official police, who were less sensitive to preserving evidence. In ‘The Boscombe Valley Mystery’, he exclaimed of the crime scene: ‘Oh, how
simple it would all have been had I been here before they came like a herd of buffalo and wallowed all over it.’
Thankfully, forensics plays a much greater role in modern detection work and the police are extremely well-drilled in its demands. While police
forces around the world each have their own guidelines, here are a few general tips on how forensic investigators go about their work:
Approach a crime scene with caution. Be aware of potential dangers – such as the on-going presence of a criminal or dangerous substances.
If there are any victims at the scene, they are the priority and you should seek out assistance for them in the first instance.
Secure the scene at the earliest opportunity (with rope or tape) to avoid contamination of evidence. This may offer the best hope of retrieving
key evidence. After an initial survey, log all potentially useful information.
If there are any witnesses, be sure to get their statements. Take a note of all comings and goings at the scene.
Document the position of potential pieces of evidence. If a camera is not to hand, make drawings or keep notes.
Bring in the relevant experts for jobs such as fingerprint sweeping or bloodstain analysis.
Any evidence to be taken away should be handled as delicately as possibly (hands should be gloved at all times). Each item of evidence must
be individually bagged and labelled.
An official record of the crime scene investigation should be written up as quickly as possible and handed over (with a briefing where
necessary) to the investigating officer in charge.
However closely you have read this book and feel you are prepared to follow in the Great Detective’s footsteps, do not insert yourself into a
criminal investigation. Leave it to the police!
Once Holmes had gleaned as much as he possibly could from a crime scene, he would often consolidate his investigation by further background
research of his own. This sometimes manifested itself in the form of experimentation. Holmes was infamous (particularly with Mrs Hudson) for the
‘malodorous experiments’ he undertook in his rooms and he was also variously witnessed beating cadavers to learn how far bruises may be
produced after death and attempting to ‘transfix a pig’ with a single blow.
Then there are his indexes and books of reference. Watson described how Holmes had ‘a horror of destroying documents’, and his book shelves
must have bowed under the weight of all the documentation he retained and cross-referenced. Had he lived today, Holmes may have regarded the
era of the internet and the all-seeing search engine as his personal paradise. We might only imagine his joy at the prospect of being able to locate
virtually any piece of information by typing a few words on a keyboard.
But before we get carried away with the thought that we are somehow masters of an information age, be warned! In 2011, an article appeared in
the journal Science, entitled ‘Google Effects on Memory: Cognitive Consequences of Having Information at Our Fingertips’. It was authored by
Betsy Sparrow, a psychologist at Columbia University, and reflected on the findings of a research project that she had co-led. She wrote:
Since the advent of search engines, we are reorganizing the way we remember things … Our brains rely on the internet for memory in much
the same way they rely on the memory of a friend, family member or co-worker. We remember less through knowing information itself than by
knowing where the information can be found.
What her study discovered was that we are far more likely to retain in our memories information that could not easily be found on the internet.
However, where information could be retrieved from the web, respondents remembered how they could find that information again (e.g. through
typing in a specific web address or search term) rather than the information itself. It is rather like remembering the name of a specific file within a
particular filing cabinet, rather than the pertinent information within the file.
In truth, this is not as modern a phenomenon as we might assume. In the fourth century BC, Plato wrote The Phaedrus, in which Socrates is
depicted narrating the tale of Thamus, an Egyptian king who hosted the god Theuth, among whose many achievements was said to be the
invention of writing. Socrates spoke thus:
You, who are the father of writing, have out of fondness for your offspring attributed to it quite the opposite of its real function. Those who
acquire it will cease to exercise their memory and become forgetful; they will rely on writing to bring things to their remembrance by external
signs instead of by their own internal resources. What you have discovered is a receipt for recollection, not for memory.
(TRANSLATED BY WALTER HAMILTON, PENGUIN, 1973)