Sitting across a table with a detainee from the militant Islamic group Jemaah Islamiah (JI) around 2003, psychologist Jansen Ang was puzzled when the man confessed to having taken archery courses.
Why archery, and how relevant was it in today's terror attacks, he asked.
The prisoner replied: A true warrior is one who knows how to shoot while riding horseback.
To many this might sound archaic, but to the JI members, it was possible because they had been brainwashed to believe they were warriors in a holy war against enemies of Islam.
"It was the JI's way of believing in an ideology and sustaining their belief in it," says Mr Ang, 43, senior principal psychologist with the Singapore Police Force.
The JI clandestine network was smashed in two security clampdowns in 2001 and 2002. Since that first arrest, more than 60 have been detained for their involvement in terrorism-related activities. Of these, more than two-thirds have been released.
All 64 men locked up were dead serious about executing their cruel plot to kill many in Singapore, according to the 2003 government White Paper on the JI arrests and the threat of terrorism.
Internal Security Department (ISD) officers found in their haul topographical maps with marked-out areas which were "kill zones".
Hunting knives for jungle survival and bomb-making devices were also confiscated.
The JI had planned to blow up water pipes, Changi Airport, foreign embassies and companies.
To understand what motivated JI members, the ISD approached psychologists in the public service to interview 31 men nabbed in 2001 and 2002.
The ISD was keen to know why ordinary men with no criminal backgrounds were prepared to carry out horrific criminal acts in the name of religion.
Among the four senior psychologists approached was Mr Ang. Their work started in 2002 and took four years to complete.
"Before meeting the detainees, we had long sessions on the approaches to use. Should we challenge them or let them talk freely?" he recalls.
Since joining the Police Psychological Unit in 1995, Mr Ang has worked in the police crisis negotiation unit and the police psychological unit which counselled cops. He is now a deputy director at the Home Team Behavioural Sciences Centre.
He graduated in 1995 with an honours degree in social science in psychology from the National University of Singapore. In 2001, he obtained his master's of science in forensic psychology from the University of Surrey, Britain.
"When I heard the news of the arrests, I kept asking myself 'how can this happen in Singapore and what is going on in the minds of these people'.
"We took psychological snapshots of the detainees' minds, asking the 'who, how and why' questions," he says.
The detainees were motivated by the power of the deviant JI ideology, which was linked to Al-Qaeda's plans to destroy the United States and its allies, and to establish pan-Islamic caliphates.
Another finding, he says, was the family connections among JI members. Brothers and bro-thers-in-law joined and remained in JI because of kinship ties.
Arresting and detaining terrorists is just one part of a long-term counter-terrorism strategy.
After the horrendous Sept 11, 2001 Al-Qaeda attack in the US, more psychologists were involved in understanding the enemy. Psychologists, who study the science of the mind, were included in interview teams as they are trained to understand what makes a person tick.
Psychologist and security expert John Horgan says terrorists are ordinary people, not crazed psychotics suffering from depression or emotional disturbances.
Psychologists can see patterns in behaviour by analysing a terrorist's denial and deception made in numerous interviews, reveals Dr Mike Gelles. He is the former chief psychologist for the US Naval Criminal Investigative Service. He headed a team that visited Singapore in 2010 to study its counter-terrorism strategies.
Mr Ang reveals that in their sessions, psychologists drew up profiles of all the jailed men. Many of them were very intelligent and fully understood what they were dabbling in, he says.
They chose terror because they wanted to stand up and fight for Muslims whom they believed were being persecuted in other parts of the world.
Apart from assisting with the interview process, psychologists taught the detainees ways of managing their emotions.
Their findings helped the ISD dismantle the JI psychology tactics.
During recruitment processes lasting an average of 18 months, charismatic JI leaders made the recruits feel important and valuable, says Mr Ang.
Those who were prepared to die in terror attacks against Singapore were promised martyrdom.
Using manipulation methods, JI made members take an oath of allegiance to JI leaders such as Ibrahim Maidin.
In their fiery speeches, he and other charismatic JI leaders stoked up feelings of anger against the West.
"Members were told that what they were doing was important and that the time for action had arrived," says Mr Ang.
Tough nut to crack
The toughest detainees to crack were those who blocked efforts to break down their radical belief system, states Mr Ang.
This group argued that rehabilitation was not relevant to them as values of inter-religious tolerance were concocted by infidels.
Psychologists, ISD officers and Muslim clerics jointly created strategies to disentangle detainees from these forms of twisted thinking.
While Muslim clerics used Islamic teachings to rebut the deviant JI teachings, psychologists focused on mind matters.
When asked if he was initially worried about doing work with detainees, Mr Ang replies: "Yes".
"I was quite concerned about my safety and my family's safety. The detainees had planned to blow up buildings. The entire syndicate had not been destroyed and there were sympathisers," he says.
"I put aside these feelings and concentrated on the task of making sense of a unique phenomenon that had occurred here."
Winning terrorists' hearts and minds
If terrorists are to be rehabilitated successfully, the psychological aspects of reintegrating them into society are important, say security experts.
Rehabilitation work on rebels from the Liberation Tigers of Tamil Eelam (LTTE) in Sri Lanka incorporated methods used in Singapore, revealed clinical psychologist Malkanthi Hettiarachchi.
After the LTTE's defeat in 2009 by Sri Lankan forces, the government decided to break the cycle of violence for more than 11,000 rebels who either surrendered or were captured.
"Singapore's rehabilitation model, considered one of the best global programmes with its large number of psychologists and religious counsellors, was particularly instructive," said the expert who worked with the Sri Lanka Security Forces in the field of rehabilitation and training.
The methods adapted from the Singapore model included education and job training.
Formal education programmes were provided for many who could not read or write.
Vocational training was also given by Sri Lankan blue-chip companies.
Family members were allowed to visit the former rebels in a relaxed atmosphere. These visits helped restore the fragmented family bonds.
By 2012, the majority of the former rebels had been reintegrated into society, she said.
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