Police stun device use can be deadly in some situations, expert warns

Police used a stun device on a man with an intellectual disability at a service housing unit in Espoo on August 14. The man later died in hospital. Yle spoke to Henri Rikander, an associate professor of police law at the University of Eastern Finland, about how the devices work and when they may be used.

The Office of the Prosecutor General will decide in the coming days whether to launch a preliminary investigation into the incident.

How the device works

A stun device fires two probes that attach to a person. A voltage of 50,000 volts passes between them, causing the muscles to contract and the person to fall.

Rikander said the device can be used either by firing the probes or by touching a person from close range.

“The stun device causes two kinds of injuries. The probes that penetrate beneath the skin cause the first injury, and the fall causes the second,” Rikander said.

Police officers have two levels of force options: firearms, and less lethal tools such as police dogs, batons, OC spray, stun devices and projectile launchers.

“The police must choose the least forceful effective tool for each situation. Not all tools work in all situations,” Rikander said.

What happened in Espoo

Police were called to the service housing unit twice on consecutive days. On August 13, officers went to calm the situation after staff reported that the man was behaving aggressively. Police were called again the following day, and the violent behaviour continued when the patrol arrived. Officers eventually used a stun device.

The Police Crimes Unit at the Office of the Prosecutor General is assessing whether to begin a preliminary investigation into the actions of the officer who used the device.

Rikander said it was very rare for the use of a stun device to cause serious injury or death. However, he recalled cases in which the device had been used, for example, at the top of a staircase.

“For this reason, a stun device must not be used in certain situations, such as on stairs or in high places,” he said.

Although the device delivers a powerful electric shock, studies show that it does not generally pose a risk to heart health. In individual cases, however, its use has contributed to heart problems, according to Rikander.

Use has increased

Police in Finland use stun devices around 500 times a year. The figure has nearly tripled since 2010.

According to Rikander, the increase is mainly due to the larger number of devices in use, meaning that more police officers now have access to them.

Rikander said the police’s internal guidance on using stun devices was adequate, but that decisions about the use of force in different situations rely on the judgement of individual officers.