He did not think his revolver would fire when he toyed with the weapon while on duty as an auxiliary police officer at the Tuas Checkpoint.

On the second day of his trial for committing a rash act to endanger human life, Gregory Lai Kar Jun, 23, who used to be a Certis Cisco corporal, admitted yesterday that he had pointed the revolver towards the ground and squeezed the trigger, causing one round to be fired.

When District Judge Hamidah Ibrahim asked if he had chosen to take the risk, Lai pondered over the question for around 10 seconds before replying: "Yes."

Lai, who is now a GrabCar driver, is accused of firing the revolver at the checkpoint at around 2pm on Aug 13, 2015.

He also faces a charge of intentionally obstructing the course of justice, by hiding the discharged round in a traffic wand. Then, to cover his tracks, he allegedly threw a second bullet into a toilet at the checkpoint, so that it would appear that he had lost two rounds.

He faces a third charge of lying to a policeman about the bullets the next day.

Lai told the court yesterday that he had placed one round inside his revolver on Aug 13. He said a colleague, Muhammad Dzul Adhar Azmi, 22, saw him do this.

In his police statement on Aug 19, 2015, Lai said: "What I know is that if the round was at the 12 o'clock point, it would come off but what I did not know was that if the round was at the 2 o'clock point, it would also come off."

In that same statement, Lai said he had put the bullet in the gun at the "2 o'clock point".

Lai said he and Dzul were shocked when the bullet was fired.

They looked for the discharged round and Lai found part of it under a table about an hour later. Lai said he came up with the cover-up plan.

He said in his statement: "At about 4pm or 5pm, I took the expended bullet and hid it in the traffic wand, the battery compartment, for the meantime first while Dzul watched me.

"Dzul then helped me bring it out but what time he brought it out and disposed of it, I do not know."

Lai said he then threw a second bullet in the toilet.

"I then reported to Ops Room that I lost two bullets," he added.

In his statement, Lai also admitted that he did not know what he was thinking when he decided to play with the weapon.

Dzul was jailed for three weeks and fined $2,000 on Oct 21 last year, after he pleaded guilty to intentionally obstructing the course of justice and failing to inform the police about the rash act that Lai allegedly committed.

The trial continues today with the prosecution set to question Lai over his testimony. If found guilty of intentionally obstructing the course of justice, Lai faces up to seven years in jail and a fine.