Imagine an excruciating pain, a pain so bad that on a scale of one to 10 "it's probably a nine, maybe even a 10," Thomas Schilken says.

"It's a feeling you don't forget," he explains in a matter-of-fact voice. 

He's talking about being "tasered" — hit, that is, by a Taser stun gun.

It's a weapon that fires two live wires connected to small projectiles. Once these pierce a target's clothing or skin, a powerful electric current surges through the person's body, causing muscles to spasm painfully.

Those who have been hit are unable to control their bodies and crash to the floor. 

'Excruciating' experience

Search YouTube for "Taser" and "police," and you will find countless clips of officers firing at targets, who collapse uncontrollably post-impact, their faces contorted in pain.

After a few seconds, the effect wears off and the probes can be pulled from the target's body. Except for mostly small puncture wounds, there are no visible traces of the stun gun's use. And, as soon as the current is switched off, the person can move normally again. 

It's an experience that leaves you "knackered," Schilken says.

He should know: Schilken has been tasered twice and, he admits, he'd prefer not to ever have to feel that excruciating pain again. 

Berlin and other states piloting Taser use

Schilken is a weapons and operations instructor at the Police Academy in the western German state of Rhineland-Palatinate.

A year ago, he started training officers to use stun guns, or Tasers as they are often referred to, after the US manufacturer Taser International (recently renamed Axon), which invented the gun.

While police special forces here have long had Tasers, several German states, including the capital, Berlin, are piloting their use.

Read more: Berlin police launch test phase of divisive Taser-guns

And two states, Rhineland-Palatinate and Hesse, are currently rolling out Tasers among all police patrol units.

For now, the federal police force, which provides security at all airports, train stations and national borders, is not planning to use the stun gun.

A weapon for 'extreme situations'

Axon, which often includes the hashtag "protectlife" in its tweets, has marketed the Taser as the safe weapon of choice that protects police officers against mounting violence, but also protects those they have to take action against in the course of duty.

Several states agree. A spokesman for Rhineland-Palatinate's Interior Ministry told DW that Tasers were being introduced for operations against people in "extreme situations" who, following drug use or severe intoxication, no longer responded to pepper spray and were acting aggressively and irrationally. 

Tasers, the spokesman added, could also be used if people with mental disorders had to be admitted to hospital against their will.

Berlin, for one, is training officers to potentially deploy Tasers in suicide cases, including in hospitals.

 Alternative to firing a shot?

One police officer, a thoughtful and genial man who serves in a state that for now is not planning to introduce Tasers, said he was "disappointed that we're not getting Tasers."

He told DW of two close colleagues who had to undergo long-term counseling after they shot and seriously injured knife-wielding attackers. One of the victims is now severely disabled.

One officer was so rattled by the shooting that he might never be able to take up a gun again when he finally returns to the force after a prolonged leave of absence.

"Psychologically, it's really difficult to process the fact that you shot someone who 'only' had a knife," the police officer told DW. That's why he would welcome a less lethal, yet as he sees it, "extremely effective weapon."

And, he added, "if you're forced to kneel on someone's chest to physically restrain them, that can also seriously injure and even kill them."  

Four deaths following Taser use

But Tasers aren't completely risk-free either: Since the introduction of the pilot schemes in the last one-and-a-half years, at least two people have died after being shot with Tasers by police officers in Hesse and Rhineland-Palatinate. And two other deaths occurred after stun guns were used by police special forces in Hesse and Bavaria.

Investigations are ongoing in all cases, but so far have found no direct link to the use of the Taser.

In all cases, the victims seem to have had prior mental and medical conditions, including heart problems, or been under the influence of drugs.

In another instance in Rhineland-Palatine, DW has learned, the probes became stuck in a target's chest and had to be surgically removed in hospital.

Read more: US police taser 87-year-old grandmother 

In a written response to DW, Axon claimed that there have only been 26 Taser-related deaths "from falls and fire" since the development of their stun gun 25 years ago. The latter refers to burn injuries caused by sparks.

Axon has yet to publicly acknowledge any death directly caused by the 50,000-volt electric current released by a Taser gun. 

But this contrasts with an ongoing in-depth investigation by Reuters news agency. So far, it has found that of the more than 1,000 deaths following the use of the stun guns in the US since the early 2000s, autopsy reports have cited Taser shocks as a cause or contributor to death in 153 cases.

Shock Tactics: Reuters Taser Tracker

The same report has also highlighted the close ties the company had forged with police, medical examiners and consultants, including paying medical experts.

Given the controversy around the use of Tasers, the spokeswoman for the public prosecutor's office investigating one of the cases in Germany told DW that it had requested four medical reports.

"We don't want to be accused of sweeping anything under the carpet," she said.

Difficult to prove

The drawn-out investigation highlights the difficulty in conclusively linking a weapon that leaves no trace to the cause of death. "It's not as if it's written on the heart why a person died," Thomas Deneke, a cardiologist in Bavaria, told DW.

The problem, he said, was that there was very little academic literature. "It's not as if you can run a human trial with people with heart conditions."

Experts tend to agree that those with prior medical conditions, particularly heart disease, coupled with the acute stress of a difficult situation, are at a greater risk of dying after being tasered.

It also seems clear that drug use and certain medication may be dangerous, "but no one knows which drugs or medication exactly," Deneke told DW.

But this latter high-risk group is often cited in potential deployment scenarios: Spokespeople for several states piloting or rolling out Tasers referred to their use against people acting aggressively or irrationally, following drug use or medication.

In a PowerPoint presentation developed for a training course for instructors, which DW has seen, Axon lists pregnant women, the elderly, small children and thin people as "higher-risk populations."

Taser "use on these individuals could increase the risk of death or serious injury," the slide states.

Read more: When smart devices pass secrets to the police

Tasers not to be used against those with 'visible heart conditions'

Instructors in Germany, many of whom were trained by Axon representatives, were adamant that they clearly communicate in their training sessions that Tasers are not to be used against high-risk groups.

Instructor Schilken told DW that in Rhineland-Palatinate, officers are banned from using the stun guns against people with "visible heart conditions," children younger than 14 years old, or pregnant women, except in life-and-death situations.

But, he conceded: "I'm a policeman, not a doctor." And, he added: "I don't know a person's medical history."

Guidelines here also stress that Tasers are not to be deployed when a target is running, standing at a precipice or close to water, to avoid dangerous injuries caused by falling.

In a written response to DW, a communications manager for Axon told DW that while Tasers were "not risk-free," they had "proven to be the safest and most effective less-lethal use of force tool available to law enforcement."

Potential for huge market in Europe

And this is a message that Axon is pushing in Europe: Given the potential for a huge market — with Italy and Belgium examples of other European countries currently piloting the Taser — the company has a lobbying presence in Europe. Its representatives reach out to police departments and trade unions and are regulars at the annual European Police Congress in Germany. Earlier this year, an Axon representative sat on a panel on violence against police officers.

While Axon declined to provide sales figures for individual countries, it said that by the end of 2018, it had sold 144,000 Tasers worldwide. On its website, it boasts to have provided its stun gun to more than 17,000 law enforcement agencies. 

In Germany, the states piloting Tasers have reported a very restrictive use of the weapon so far: In most instances, officers merely threatened to deploy the gun.

In Berlin, it has only been fired three times since the introduction of the pilot scheme, in two cases to prevent a suicide.

'Additional police violence' in the Netherlands

This contrasts with the Netherlands: During the first year of a pilot phase, which began in 2017, officers deployed the Taser in 341 times. "The figures are simply mindboggling," Emile Affolter, a spokesman for the human rights organization Amnesty International in Amsterdam told DW. "It seems like the police went out and just experimented basically."

Rather than the Taser being used as an alternative to the gun or pepper spray, he said, "we're seeing additional police violence."

According to Affolter, Dutch police officers tasered several people who were already handcuffed or being held in police cells and psychiatric institutions.

In some cases, targets were tasered several times with the so-called drive stun mode, where instead of firing a shot, the gun is held against the target. While this mode is extremely painful, it does not incapacitate the body. 

That is why Affolter believes its repeated use could amount to inhumane treatment or "even torture in some cases."

The UN Committee against Torture seems to share his concern: In 2018, it called on the Netherlands to "refrain from routine distribution and use of electrical discharge weapons by police officers in their day-to-day policing" and adopt safeguards against misuse of Tasers.

Since then, following the introduction of better training, the use of stun guns in the Netherlands had fallen considerably, according to Affolter.

Rollout continues

In Germany, the police officers DW contacted said such an excessive use of force would be unthinkable. In Berlin, the use of the drive stun mode is banned and in Rhineland-Palatinate, instructor Schilken says, it's not a "priority" of the training.

Throughout his interview with DW, Schilken stressed repeatedly that the aim of his training was a "respectful" use of the Taser. And, he said, the training included first aid and general safety measures.

Axon seems to be well aware of the concerns around the use of its Taser here. In order "to meet the needs of our German customers," a communications manager told DW, it had incorporated additional time into its curriculum for discussion of medical effects.

So far, the four deaths following the use of Taser guns don't seem to be deterring the rollout of the gun. Both Hesse and Rhineland-Palatinate told DW they would abide by their decision to equip their regular police forces with Tasers.

And with several other states piloting their use, it's possible that others will soon follow suit. If that is the case, more people will potentially experience that excruciating, unforgettable pain.

Thomas Allinson contributed to this report. 

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