Year 2022
February 2022

Stun devices and pepper balls: Elite prison security force using tech to handle violent inmates

February 09, 2022
By Aqil Haziq Mahmud

Singapore Prisons Emergency Action Response (SPEAR) force officers before storming a cell. (Photo: CNA/Aqil Haziq Mahmud)

SINGAPORE: Deep in one of Changi Prison’s cell blocks, an “inmate” is creating a ruckus.

There are obvious signs of escalation: The inmate is shouting and pounding on the walls. He has covered the surveillance camera in his cell and obscured the window on his door, preventing officers from seeing his next move.

The Singapore Prisons Emergency Action Response (SPEAR) force, a fully armed, elite tactical unit trained to respond to security breaches or unrest, is activated.

This was part of a demonstration put up by the unit at its base in Changi Prison on Tuesday (Feb 8) to showcase the technology used in handling violent inmates.

The Singapore Prison Service (SPS) said in a news release that SPEAR troopers are activated to support operational staff in managing more serious or violent offenders.

“SPS has been investing in technology and training of our officers to strengthen our operational capability to respond to incidents of violence amongst inmates,” the agency said.

This comes as its latest statistics revealed that the prison assault rate for financial year 2021 is projected to be around 46 assaults per 10,000 inmates.

SPS said the rate has “stabilised” since FY2019 and FY2020, when it was about 46 and 47 respectively. But the rate has increased in the past few years, when it ranged from 24.4 in FY2016 to 39.1 in FY2018.

The assaults typically cover attacks by inmates on prison officers or fellow inmates, during which victims sustain serious injuries, SPS said.

SPEAR officers approaching a cell. (Photo: CNA/Aqil Haziq Mahmud)

SPEAR troopers get activated roughly once every two weeks, its deputy commanding officer Superintendent of Prisons (Supt) Derry Teh revealed, although he said not every activation requires the use of force.

“Sometimes by (our) mere presence and reputation, the inmates know they should desist and not put up a good struggle,” he said.

“In quite a few (incidents), the inmates stood down upon hearing our (vehicle) siren or seeing us giving them the last warning. So, we will adjust our force level accordingly.”

When asked about the threshold for activation and whether two inmates fighting is a reasonable trigger, Supt Teh said the force does not question any call for support.

“We always go knowing that they really need our help,” he said.

“The different profile of inmates can play a different role. For example, they could be martial arts-trained or foreigners who are especially large-sized. They could be of unsound mind where their normal receptors to pain are at a much higher threshold.”

A SPEAR officer displaying his under-door camera and screen. (Photo: CNA/Aqil Haziq Mahmud)

Back to the demonstration, the stocky role-playing inmate certainly had ambitions of wreaking havoc. Stashed in his shorts was an improvised weapon, a plastic shank made from a broken kit box.

Six SPEAR officers carrying a shield and various devices approached the cell door. One of them crouched and inserted a small camera under the door. They now have eyes on the inmate, with a live video feed on a screen attached to an officer’s arm.


The officers communicated using hand signals and decided it was time to act.

One of them lifted a hatch on the cell door and shot pepper balls inside. “Oi!” the inmate shouted, presumably struggling to open his eyes.

The pepper balls are discharged using a firearm fitted with a pressurised canister. The officer can also choose to spray a pepper mist rather than shoot pellets, a technique more suitable for confined spaces where inmates could be hit by stray projectiles.

SPEAR officers storming the cell. (Photo: CNA/Aqil Haziq Mahmud)

After less than a minute, it was time for the officers to move in.

Similar to tactics used in the military – SPEAR’s predecessor, formed in 1977, was trained by Singapore Armed Forces commandos – one of the officers again lifted the hatch and threw in what looked like a stun grenade.

A distraction device emits a bright strobe light and screeching sound. (Photo: CNA/Aqil Haziq Mahmud)

The distraction device feels like a grenade in the palm (Photo:CNA/Aqil Haziq Mahmud)

It was not a grenade, but an electronic distraction device that burst into a bright strobe light with a loud screeching noise.

Three officers stormed in with the shield and subdued the inmate in a series of locks. Two of them held the inmate’s arms against a wall. The third officer pressed his arm against the inmate’s jaw and pulled his head down, shouting out the manoeuvres as he went along.

SPEAR officers retraining an inmate using close quarter techniques. (Photo: CNA/Aqil Haziq Mahmud)

SPEAR officers retraining an inmate using close quarter techniques. (Photo: CNA/Aqil Haziq Mahmud)

SPEAR officers retraining an inmate using close quarter techniques. (Photo: CNA/Aqil Haziq Mahmud)

SPEAR officers retraining an inmate using close quarter techniques. (Photo: CNA/Aqil Haziq Mahmud)

The inmate heaved and struggled furiously but was forced to bend forward, as officers put mechanical restraints around his wrist and pulled him out of the cell. “I will get you!” the inmate screamed.

By then, reporters were ushered into the cell for a closer look at how SPEAR officers restrain inmates using joint locks and pressure point techniques.

A SPEAR officer discharging talcum powder in place of pepper spray. (Photo: CNA/Aqil Haziq Mahmud)

The prickly smell of talcum powder – used during the demonstration in place of harsher pepper balls – lingered in the air, eliciting more than few sneezes from watching reporters.

With the inmate still uncooperative, the SPEAR officers put him in a yellow motorised wheelchair, used to transport inmates to their next location.

An inmate being transported on the motorised wheelchair. (Photo: CNA/Aqil Haziq Mahmud)

An inmate being transported on the motorised wheelchair. (Photo: CNA/Aqil Haziq Mahmud)

An inmate being transported on the motorised wheelchair. (Photo: CNA/Aqil Haziq Mahmud)

An inmate being transported on the motorised wheelchair (Photo: CNA/Aqil Haziq Mahmud)

An inmate being transported on the motorised wheelchair. (Photo: CNA/Aqil Haziq Mahmud)

“(The institution could) segregate them for investigation processes to take place, or there’s a need to sometimes, if they are of unsound mind, send them to medical facilities,” Supt Tay said.

The wheelchair is also equipped with tracked wheels to move up and down stairs with the push of a button.

Previously, four SPEAR officers would escort an uncooperative inmate down the stairs by pressing him against the handrails and moving in tandem, a considerably slower and exhausting process.


Supt Teh said SPEAR’s use of technology is not linked to the prison assault rate, highlighting that the “progressive” unit regularly reviews its tactics and equipment.

“But if we ever see a new situation that needs a new capability, then we will of course try to close the gap as far as possible,” he said.

For instance during the COVID-19 pandemic, SPEAR officers decided that it would be undesirable to use pepper balls and have inmates coughing and sneezing. So the unit did some research and switched to lemongrass and menthol as a milder but equally effective irritant.

The robot is fitted with parts 3D printed by an in-house SPEAR team (Photo: CNA/Aqil Haziq Mahmud)

Supt Teh revealed that the unit is also testing a robot that can send back live video as well as spray irritants and emit distracting light and sound to respond to security incidents in lockdown scenarios.

“This is useful in a grilled setting where inmates have (produced) a lot of biowaste, and you might not want a human to go in person to appreciate the situation,” he said. “All these tools will allow us to do it in a safer manner.”

Source: CNA/hz(cy)
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