Do Taser Assault Victims Suffer Miscarriages of Justice?

Taser weapons have serious effects and their use may lead to miscarriages of justice.
Kevin Donoghue, solicitor.

By Kevin Donoghue, solicitor

A recent study in America suggests that Taser “stun-guns” cause short-term dementia-like effects in victims.

This raises questions about their use and, in particular, whether miscarriages of justice occur when the police question suspects shortly after using the weapons.

Independent Taser Study

The study, reported by Drexel University, and funded by the U.S. Department of Justice, is reported to be the first time the Taser weapon has been tested in a clinical trial outside of those set up by Taser International, the company that develops, makes, and sells them.

142 young people were tested. They were separated into four groups:

  1. 37 people in the control group did nothing
  2. 32 hit a punching bag (to simulate the excited physical state they might feel during a police incident)
  3. 35 people received 5 second Taser shocks
  4. 38 hit the punching bag AND received the 5 second shocks.

One of the report’s authors, Robert J. Kane, PhD, said that the participants were subjected to a “battery of cognitive instruments” (tests) at various times:

  1. At the preliminary screening stage
  2. Right before treatment exposure (varied depending on group)
  3. Immediately after treatment
  4. One hour later
  5. One week later.

Their test scores were compared within their own groups, and across all four groups, to compare any changes in cognitive functioning.

The most significant result came on the Hopkins Verbal Learning Test (“HVLT”). This test assesses verbal learning and memory and can show anything from mild learning difficulties to dementia. The study participants were asked to learn, then recall, a series of 12 words over different times.

Before using the Taser, the average HVLT score for each group was 26, just above the national average. Afterwards, a quarter of both Taser groups (3 and 4) scored below 20, giving them the average cognitive functioning of 79-year-old adults. The decline in cognitive functioning was said to be “comparable to dementia”.

The Taser caused statistically significant reductions in verbal learning and memory for, on average, less than an hour. And Michael D. White, PhD, who co-authored the report, said that “our test administrators could clearly observe the difficulty many participants had with the HVLT after Taser exposure.”

As well as these scientifically provable changes, the researchers found that the use of a Taser also caused “significant negative change in several subjective state self-measures, including concentration difficulty, anxiety level and feeling overwhelmed”.

Dr. Kane said, “Being shocked had a traumatic effect on some participants. Some were emotionally debilitated by the experience.”

He also pointed out that the test subjects were not typical of Taser assault victims. They were young, healthy, used to taking tests, drug and alcohol-free. They were also in a controlled environment (a hospital) with medical staff on hand, and understood that they were taking part in a scientific study.

He said, “We would expect ‘typical’ suspects – who may be high, drunk or mentally ill and in crisis at the time of exposure – to experience even greater impairment to cognitive functioning as the result of Taser exposure.”

Consequences of Taser Use

The results of the study have significant implications for the public, police policy, and judicial procedures.

Tasers are used by law enforcement world-wide, including the UK. The Metropolitan Police use the X26 Taser and describe on the Force’s website how “When fired Taser delivers a sequence of very short high voltage pulses that result in the loss of voluntary muscle control causing the subject to fall to the ground or freeze. In the X26 the voltage peaks at 50,000 volts…”.

I previously wrote about the worrying increase in Taser use here: How Police Taser Use is Failing Us All. I was concerned when Chief Superintendent Paul Morrison, Head of Operations Command at Sussex and Surrey Police, discussed a case involving the use of a Taser on 14-year-old girl and described the Taser as “a low level of force” which was preferable to a baton.

Nothing could be further from the truth. Tasers are potentially deadly weapons and should only be used as a last resort. They have serious physical, emotional, and (we now know) mental effects.

Miscarriage of Justice

In addition, the Drexel University report opens up another potentially life-changing risk: miscarriages of justice.

The police must read the following caution before questioning someone about a crime:


That’s 37 words, more than three times the number in the Hopkins Verbal Learning Test which the Taser study used to test cognitive impairment. If fit, healthy, sober, above-average adults had dementia-like effects trying to learn and recall 12 words after being Tased, what chance would they have with 37? More importantly, how would the “typical” suspects mentioned by Dr. Kane cope?

Having a caution read to you is not the same as understanding it.

The Taser victim may:

  • not understand the caution or be able to think it through;
  • waive their rights to speak to a solicitor or have one present in an interview;
  • be more open to persuasive interview techniques; and
  • give inaccurate information.

Ultimately, the evidence gained might wrongly prove their guilt at court, resulting in a wrongful conviction and miscarriage of justice.

Custody Record Comments

After using a Taser, the police do not have to wait a minimum period of time before questioning someone. Provided an officer has read the caution to a Taser victim suspect, the police can start the interview immediately.

Because the majority of Taser victims in the study recovered from the cognitive effects within an hour, the report’s authors suggest delaying the interview to avoid potential miscarriages of justice. “What would it cost police to wait 60 minutes after a Taser deployment before engaging suspects in custodial interrogations?” they say.

That alone might be good enough in the USA. In the UK we have other issues.

This is because, in my experience as a solicitor who specialises in civil actions against the police, it is unlikely that a Taser victim would be interviewed within an hour. After being Tased, arrested, cautioned, taken to a police station, booked in, processed, and seen by a medic, more than an hour would normally have passed. The majority of people would have shaken off the dementia-like effects.

But the Custody Record is often filled out within that time, as it is started when the suspect is presented before the Custody Officer at the police station. It is a very powerful tool in the prosecution’s hands as it is a contemporaneous record which can be relied upon at court.

And it is more than just a record of detention. There are two sections where the suspect’s comments are recorded:

  1. The first section, “Arrest”, records “Comments made when facts of arrest explained”. These comments, made by the suspect immediately after the caution, are noted by the arresting officer (usually in the pocket notebook) and read to the Custody Officer with the suspect present.
  2. The second relevant section of the Custody Record (“Detention”) notes “Comments made when reasons (for detention) explained”. Anything said by the suspect before the Custody Officer is recorded.

Crucially, in both sections where the suspect’s comments are recorded they must be counter-signed and verified to be true by the suspect themselves. This makes it very difficult for the suspect and his or her legal team to them challenge later.

Knowing, as we now do, that a quarter of Taser victims suffer dementia-like effects, why should:

  • these comments, usually made within the crucial first hour, become written evidence in the Custody Record?
  • the comments be verified to be true by the suspect when they may not know what they said or what they are signing?
  • these early comments gain further legitimacy by being referred to in later (formal) recorded interviews?
  • interviewing officers be allowed to refer to them to put pressure on Tased suspects?
  • prosecutors be allowed to refer to them at Court?

Flawed System

Allowing the police to use post-caution and detention comments from Taser assault victims may lead to miscarriages of justice, which are bad for everyone, not just the wrongfully convicted victim who is denied their liberty. Confidence in the legal system and the Rule of Law is diminished, the financial costs to the State and society are significant, and there is the risk that the person who committed the crime will re-offend, causing further unnecessary harm.

Politicians, the police, and public now know enough about the serious physical, emotional, and mental effects of Tasers. Miscarriages of justice are likely to occur if the present system remains. It’s time for a change.


Kevin Donoghue is the Solicitor Director of Donoghue Solicitors, a firm which specialises in civil actions against the police and people who have suffered due to the unlawful use of Taser weapons.