One of the more interesting assignments in my university studies involved interviewing someone about their working life. I chose my husband, who has spent most of his career with the Queensland Police Service and works in forensic fingerprint examination.
He is usually a very private person, so I appreciated his willingness to let me ask questions about work he has been doing for many years.
What struck me most was how much fingerprint examination has changed during his career.
The old image of a fingerprint expert hunched over a desk with a magnifying glass is increasingly a thing of the past. Once, a crime-scene photograph had to be taken on film, developed and physically sent to the fingerprint bureau. Examiners used classification systems to search through large collections of paper fingerprint records by hand.
Today, digital images can arrive from a crime scene almost immediately. Fingerprints can be searched through national databases, images enlarged and enhanced on screen, and possible matches returned within minutes rather than days or weeks.
Technology has also made it possible to recover evidence that once could not be detected at all. New light sources, chemicals and laboratory techniques can reveal fingerprints beneath paint or on difficult surfaces. Fingerprint and DNA specialists increasingly work alongside one another, each needing to understand enough about the other discipline to avoid destroying potentially useful evidence.
But faster technology does not remove the need for human judgment.
A fingerprint identification is not accepted simply because one examiner, or a computer, says it is a match. Other qualified experts independently check the comparison before it is confirmed.
My husband explained the limitations of automated matching with an analogy I particularly liked.
A computer searching fingerprints is a little like being asked to find the Southern Cross in the night sky. It might identify a group of stars that has the right general pattern, but an experienced person knows to look for the pointers and other surrounding features before deciding it is the true Southern Cross rather than a similar formation.
The same principle applies to fingerprints. A computer can nominate a likely match, but somebody still has to understand what they are looking at.
COVID added another layer of complexity. Some forensic work could be done remotely, but important systems could only be accessed from designated terminals, while laboratory work, crime scenes and other practical duties obviously could not be done from home. At the same time, police staff were being diverted to border and quarantine duties.
The result was that fewer people remained in the office to do the work that could only be done there.
Listening to my husband describe all this made me realise how much modern forensic work sits at the intersection of old and new. Some skills that once took years to develop have become less important, while entirely new ones have emerged. Tasks that once took weeks can sometimes be completed in minutes.
Yet despite enormous technological change, one thing has remained.
Someone still has to look at the evidence and decide what it means.
As my husband put it, computers are extraordinarily useful, but they are only as good as the systems behind them. In work where a mistake could contribute to an innocent person being arrested, there is good reason not to surrender human judgment too quickly.