What effect does diabetes have on the criminal law (motoring)?

What is diabetes?

Diabetes is a common chronic condition affecting around four million people in the UK. It is the fastest growing health problem in the UK. Diabetes is where the pancreas cannot regulate the level of blood sugar in the bloodstream. Many sufferers require insulin injections to help them manage their condition.

In some cases, diabetes can have a huge effect on the individual. There are two types of diabetes: hyperglycemia and hypoglycemia.

What’s the difference between hyperglycemia and hypoglycemia?

Hyperglycemia is where the individual with diabetes has too much sugar in their body. Typical symptoms include urinating more than usual, weakness, tiredness, weight loss, increased thirst and blurred vision.

With hypoglycemia, the sugar level is too low. Typical symptoms are hunger, feeling dizzy, irritability, shaking, and paleness. Hypoglycemia can cause effects which are similar to alcohol consumption. Hyperglycemia can also cause similar mental impairment, but to a lesser degree and with a much slower onset.

Why is diabetes important in the context of motoring offences?

Given that the effects of hyperglycemia and hypoglycemia can mimic the effects of alcohol, there is a greater risk of dangerous or careless driving. Accordingly, drivers who have diabetes must adhere to certain conditions imposed by the Driver and Vehicle Licensing Agency (DVLA). They must also make sure their insurance company is informed of their condition.

The driver must notify the DVLA of their condition. Many will be prohibited from driving Heavy Goods Vehicles (HGVs). In addition, to reach the required visual standards all diabetic drivers of cars and motorcycles must recognise the symptoms of hypoglycemia and are issued with a detailed letter providing advice from the DVLA. This is vital so that drivers with diabetes can recognise when they are suffering from low blood sugar, and take the necessary action (usually pulling over and stopping) so that they do not endanger the lives of other road users.

Are there any other offences diabetes sufferers are at risk of committing?

As well as potential motoring offences, individuals with diabetes have been known to have been arrested for certain public order and violent offences. However, there are defences available of ‘automatism’ and insanity.

What does the criminal law say about automatism?

The criminal law of England and Wales recognises incapacity as a defence to a criminal charge. Incapacity can be (sane) automatism, and insanity – which includes insane automatism. The distinction between the two depends on whether the cause is internal or external. Individuals with diabetes who have been charged with an offence whilst suffering from hypoglycemia can plead automatism as a defence.

To successfully plead automatism, the defendant must be able to show:

  • That they have suffered from a complete loss of voluntary control, and
  • This was caused by an external factor – ie. they were not at fault in losing their capacity

What must a defendant show to be able to plead insanity?

For a defendant to successfully plead insanity, they must be able to show that there was a disease of the mind. A disease of the mind can include physical disorders such as diabetes as well as physciatric and neurological conditions.

When can a defendant be acquitted in these circumstances?

When hypoglycemia occurs without prior warning or fault, there may be no liability for crimes requiring intent. However, if the individual has been reckless or negligent in relation to their diabetes they may be convicted on the basis of self-induced incapacity.

This means that a defendant who was reckless in managing their diabetes knowing the possible consequences of not properly managing the condition, may have the requisite knowledge of a crime of basic intent required to result in a conviction as if they were voluntarily intoxicated.

What is the difference between basic and specific intent?

An example of a crime involving specific intent is murder – the defendant must have specifically intended to kill their victim to be convicted. So if the defendant was suffering from a hypoglycemic attack at the time, they could plead the defence of automatism. However, this would not be a complete defence and would result in the charge reduced to manslaughter.

An example of a crime involving basic intent is battery, which requires that the application of unlawful force was intended, or that the defendant was reckless. This means a defendant who was suffering from a hypoglycemic attack cannot rely on it as a defence to a battery charge.

In relation to motoring offences, the diabetic defendant will most likely be convicted if they decide to drive (or to continue to drive) whilst knowingly exhibiting symptoms of hypoglycaemia, and will be unable to plead automatism.

When must a diabetic inform the DVLA of their condition?

The DVLA must be informed if one of the following happens:

  • That an individual suffers more than one episode of disabling hypoglycemia within 12 months or if their carer feels that they are at a high risk of developing disabling hypoglycemia
  • That an individual develops impaired awareness of hypoglycemia – that they have difficulty recognising the symptoms of low blood sugar
  • That an individual suffers disabling hypoglycemia whilst driving

What precautions should drivers who are required to take insulin follow when driving?

Drivers with insulin treated diabetes are advised to take the following precautions:

  • To not drive if they feel hypoglycemic
  • If hypoglycemia develops whilst driving to stop the vehicle as soon as possible in a safe location turning of the engine and taking themselves from the driving seat
  • To not resume driving until 45 minutes after the blood glucose level has returned to normal
  • To always keep an emergency supply of fast acting carbohydrate such as glucose tablets or sweets
  • To carry personal identification indicating they have diabetes such as a bracelet in case of injury in a road traffic accident
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Article written by...
Lucy Trevelyan LLB
Lucy Trevelyan LLB

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Lucy graduated in law from the University of Greenwich, and is also an NCTJ trained journalist. A legal writer and editor with over 20 years' experience writing about the law.