IF THAT person next to you keeps mumbling to himself, repeatedly avoids eye contact or keeps his head hung low all the time, there is a high chance that he is up to no good.
Security experts say these are the signs they look out for when they try and identify threats in big crowds.
The advice came in the wake of an attack on Mr Seng Han Thong, MP (Yio Chu Kang), on Sunday when a man set him ablaze. A grassroots leader, Mr Aw Chui Seng, was also injured in the attack.
Both have since gone through skin-graft operations. At a district court yesterday, Ong Kah Chua, 70, a former cabby, was charged with injuring the two.
If convicted, he could be jailed up to 15 years or for life and be fined. Because of his age, he cannot be caned.
my paper spoke to several security firms to find out how such attacks can be prevented.
Who is at risk
Politicians, business leaders, senior management and lawyers seem to be the most susceptible.
'It includes anyone who has made a statement or was responsible for information given to the public which members of the public were uncomfortable with,' said Mr Sudhir Singh, 45, from Pico Guards.
He added that lawyers deal with sensitive things like "monetary issues or things that affect the family which might provoke people to do things".
Who are the perpetrators
'Some people who are unemployed can be quite desperate. They need to find someone to blame, and once they are fixated on a figure, they are obsessed,' said Mr Shaun Eric, 37, of AA Security.
How to lower such risks
Mr Ayob Ahmad, 46, from J C Security Services, said: 'Event organisers have to be more alert and supply more security officers.'
Mr Singh said: 'Screen anyone who comes in for such public events.' He added that security should ask to check all visitors' bags.
Other signs to look out for 'These include someone who is overdressed, such as wearing a thick jacket under the hot sun, and who looks like he is hiding something,' Mr Eric said.
Mr Surjit Singh, 47, from Actus Guards, said: 'We also look out for people who are dressed shabbily or have prominent tattoos on their arms or legs.'