Australian_Geographic_-_August_2015_AU_.

46 Australian Geographic

W

HEN PIA NAVIDA, a 37-year-old

Filipino woman, was found

brutally slaughtered in Sydney’s

Royal National Park in 1992,

the subsequent investigation

failed to identify her killer. The case found its way

onto the sad catalogue of unsolved murders on the

books of the NSW police, where it remained for the

next 23 years. If that terrible crime had happened

today, it would never have become a cold case.

By all accounts, it was a clumsy murder that should

have been easy to solve – Pia’s clothes were

left strewn around a nearby walking trail, and the

assailant hadn’t made much of an attempt to hide

her body or the murder weapon, which was a blood-

stained rock. But although all the physical evidence

was there – including blood under Pia’s fingernails

• police had no way of linking it to a suspect. So, for
  more than a decade, her body was stored in a NSW
  Police freezer, and the trail went cold.
  However, in that time, scientists sequenced the
  human genome – the total sum of our DNA – and
  the technology became reliable enough to enable
  police to identify individuals through unique sections
  of their genes. DNA is now routinely used to place

suspects at a crime scene, identify victims’ remains,

and even point police to potential suspects by com-

paring DNA left at the scene with that of known

criminals on the national database.

In the hopes that this breakthrough science might

finally give police a lead, Pia’s remains were retrieved,

and, in mid-2014, a man named Steve Isac Matthews

was finally convicted of her murder.

Although DNA evidence has been used regularly

in murder cases since the early 2000s, Pia’s was one

of the first cold cases in NSW to secure a murder

conviction using this new technology. Sharon

Neville, the assistant deputy director of the NSW

Health Pathology’s Forensic and Analytical Science

Service (FASS), remembers the entire investigation

NICK CUBBIN is a Sydney-based freelance photographer

whose work has appeared frequently in the journal. His last

assignment for us was Grub’s Up (AG 124), about the potential

for insects to feed the planet’s burgeoning population.

FIONA MACDONALD is an award-winning science writer

in Sydney. Her last story for the journal was Unseen Sydney

(AG 125), about the unusual images that can now be photo-

graphed using remote-piloted aircraft.

Fine details. Clint Cochrane, at
left, and Rebecca Douglas use a
chemical test and LED ‘Crime-Lite’
to locate biological matter on
crime scene exhibits.