3D laser scanner
A high-tech 3D laser scanner is helping to revolutionise the way
officers investigate crash scenes on the county’s major road
network.
The RIEGL VZ-400 scanner, delivered to Essex Police’s Forensic
Collision Investigation Unit in March 2012, collects detailed 3D
images of crash sites in up to half the time it currently takes an
officer to collect evidence manually.

As well as reducing the length of time a road needs to be closed
after a serious crash, the data collected can recreate a virtual
copy of the scene which can be used as an investigative aid and in
court to support or contest driver and witness statements.
Put simply, the scanner collects evidence using a laser beam to
survey and record 120,000 tiny details of the scene every second
while slowly rotating on a 360 degree axis. The web film above
helps explain how the scanner works.
Trials showed the scanners were able to collect 30 per cent more
data up to 50 per cent faster than the traditional manual methods.
In turn, average road closure times were reduced by an average of
90 minutes.

The equipment has been jointly funded by the Department of
Transport, the NPIA, Essex Police Authority and Essex County
Council.
A number of officers from the Forensic Collision Investigation Unit
at Boreham have been trained to use the equipment supplied by 3D
Laser Mapping.
Pc Duncan Thurwell from the Forensic Collision Investigation Unit
said: “The laser scanner is an amazing piece of equipment that will
reduce road closure times after fatal or serious collisions –
something we know is a source of frustration to members of the
public who rely on the roads.
“It also allows us to build a much more detailed picture of events
from evidence at the scene and turn it into a virtual 3D world
which can be used as an investigative aid, to analyse the actions
of a driver from their viewpoint or be called upon in court to test
witness evidence.
“Although the scanner is being rolled out to aid the investigation
of collisions, it can also be used at the scenes of other serious
incidents where detailed evidence needs to be captured such as
murder or rape.”