03 July 2019

Human-Trailing Dog

SPF Logo


By: J. Jaidurga, Kelvyn Vernon Owen Richard and Eswari D/O Pannerselvam

(Photos: Public Affairs Department)


Since 2010, Human-Trailing Dogs (HTDs) have not only helped solve crimes,

they were also responsible for locating missing persons. Join Police

Life as we find out more about our human-trailing fur pals from the Police

K-9 Unit!


Crime Scene K-9s


Just as the term ‘human-trailing’ suggests, HTDs are capable of detecting

and locating a person based on the ‘scent article’ left at a crime scene.

These ‘scent articles’ refer to personal items such as watches, clothes and

pillowcases that have only been used by that person. HTDs can be deployed

during crime scene investigations in areas such as Housing and Development

Board (HDB) flats, industrial parks and places of interest.


After thoroughly sniffing the ‘scent article’, HTDs will begin the trailing process.

The average human body sheds about 40,000 dead skin cells per minute and

replenishes them with new ones. These skin cells are too microscopic to be

seen by the human eye, but HTDs are able to trail a person based on the

individual’s unique odour that lingers on the dead skin cells.


Dawn of the HTDs


HTDs play a pivotal role in policing. Before they become deployable HTDs,

the selected K-9 dogs will have to undergo a rigorous training process. Since

2010, the K-9 unit has trained a total of nine dogs with the human-trailing

capability, including three retired dogs who served seven years before

retiring. A K-9 dog is chosen to be an HTD based on its ability to distinguish

specific scents and their ability to retain them. The selected dogs will then

undergo a three-month training programme comprised of three phases to

test their capabilities:


Phase 1


Trailing a subject for a distance between 100m and 250m in either rural or urban areas.


Phase 2


Trailing a subject for a distance between 250m and 400m only in urban areas.


Phase 3


Trailing a subject for a distance beyond 400m through buildings and urban areas.



After each training session, the K-9 dogs will be rewarded with ball play to

keep them motivated. To become operational, the HTD and their handler

must complete a practical assessment at the end of the three-month course

to assess their ability to trail a person for a distance between 400m and 1km.


Ready to Trail You


For over 30 years, Labrador Retrievers have been used for police work.

However, the first HTD in Singapore was not a Labrador Retriever, but was in

fact a Bloodhound. Ever since, Labrador Retrievers have been preferred as their

short fur is more suited for the local tropical climate. By being better adapted to

the local environment, these dogs can work for longer periods of time.


One example of an impeccable Labrador HTD would be the young and inspiring Ole.

Due to his excellent sniffing abilities and his drive to trail scents, Ole was selected

among several other K-9 dogs to be trained as an HTD.


SI Khoo with HTD Ole


On 4 November 2016, Ole became an operational HTD with his handler,

Station Inspector (SI) Bryan Khoo. “Ole is a confident and cheerful dog who

loves to interact with humans,” remarked SI Khoo. Due to its positive characteristics,

Ole played a significant role in the search for several individuals.


Some of the cases include:


27 Oct 2017

Search for a missing person at Little Guilin, Bukit Batok

Ole led officers to the edge of the quarry, close to the missing person’s belongings. The missing subject was eventually found in the quarry by rescue divers.


28 Jun 2018

Search for an Absent Without Official Leave person who fled from his home in Choa Chu Kang

Ole led officers across the road and towards the HDB area. Police Camera (PolCam) footage later revealed that the person had fled via the route identified by Ole.


24 Jan 2019

Search for a runaway person who ran away from roadblock at Senja Road

Ole led officers to Blk 624 Senja Road to narrow down the search area. PolCam footage revealed that the person had taken the lift and was eventually arrested at the block.



SI Chew with HTD Caesar


SI Lim with HTD Xion


Besides Ole and SI Khoo, Police Life also had the opportunity to meet HTD Caesar

and HTD Xion, with their respective handlers, SI Morgan Chew and SI Jeffrey Lim.

Let us take a look at some of the cases that these HTDs have solved:


26 Jul 2015

Search for a suspect involved in attempted rape at Choa Chu Kang

HTD Caesar led officers to the 7-11 store at Limbang Shopping Mall. Staff

informed that the person fitting the description provided by the officers had

gone into the store earlier. This provided a lead for follow-up investigations

which led to the person’s arrest.


11 Oct 2016

Search for a person involved in housebreaking at Lyndhurst Road

HTD Caesar led officers through Wilkinson Road, Branksome Road, Goodman

Road, along Geylang river and finally to a unit at Blk 6 Dakota Crescent. The

owner of the unit, who was already under custody of the Police, admitted to the



13 Oct 2018

Search for a missing tourist last seen taking a bus from

Woodlands Checkpoint

HTD Xion trailed for a total distance of 1.5 km before he led officers to a

missing person at an open car park in Woodlands Centre Road.



Our fur pals have indeed been vital in supporting the SPF’s operations. Alongside

their handlers, the HTDs will continue to play a significant role in keeping Singapore

safe and secure.

Last Updated on 03 July 2019