From the Singapore Police Force's letter, it appears that the Police Licensing and Regulatory Department's (PLRD's) screening for security guards is not as robust as it should be and needs to be improved (Police screening didn't pick up guard's secret society links; Forum Online, March 29).

The validity of the licence should also be shortened from the current five years to one or two years so that there can be more regular screenings to weed out unsuitable individuals.

It is strange that the PLRD did not immediately revoke the offending security officer's licence in 2016, when he committed theft while working as a relief guard (Security man with secret society link jailed; March 14).

Otherwise, he would not have been able to work in the same occupation last year.

All licence holders should have a clean criminal record. It must also be made clear to all security officers that their licence will be revoked if they are found guilty of a criminal offence.

Sim Eng Cheong