The shooting dead of a man by police near Bristol means an investigation is now underway by the Independent Police Complaints Commission.

Notified by a 999 call that a man with a handgun was threatening another motorist on the M5, Avon and Somerset officers intercepted a red Suzuki Swift car, stopped it on the A369 near Portbury and shot the driver.

A "non-police issue" handgun was later recovered.

Called in whenever someone dies as a result of police contact, the IPCC team assigned to the case will have to find out how many shots were fired, who fired them, whey the decision to open fire was made and whether the correct procedures were followed - in short, whether the death was lawful or unlawful.

But there are wider questions, too, which the media and public are raising about the circumstances that can lead to the police opening fire.

Some commentators have suggested that police have a ‘shoot-to-kill’ policy when deploying armed officers. So, are they right?

Do we have a shoot-to-kill policy in the UK?

This year police chiefs announced a more aggressive policy on the use of lethal force. Against a backdrop of increased police militarisation, a further 640 firearms officers were added to the force in England and Wales.

The previous approach of "locate, contain and neutralise" was also changed to "locate and confront" – making tactics more aggressive.

The approach to firing at moving vehicles was also updated in response to terror attacks in Nice, Stockholm and London. Officers now have more powerful weapons, able to penetrate strong materials such as lorry cabs.

However, these changes to policy only apply to terrorist activity, and do not indicate a pre-determined 'shoot-to-kill' policy.

(Image: Jon Kent)

The term 'shoot-to-kill' is quite often misunderstood as a pre-meditated order to shoot on sight.

But its correct definition is a reactive action taken to prevent an immediate threat to life by shooting to stop the subject from carrying out their intended or threatened course of action.

In 2015 the then Metropolitan Police commissioner, Sir Bernard Hogan-Howe, said there was no shoot-to-kill policy.

He told LBC radio: “The law says that the police can use reasonable force, firstly to stop a crime, and secondly, to arrest someone who is putting someone else in danger. If someone’s life is at risk, a police officer can intervene. If they are armed or otherwise dangerous, we can stop them.”

When can armed police open fire?

Armed police officers faced with any scenario, terror-related or otherwise, have no special legal status and are subject to criminal law, including the law governing self-defence.

They make the decision to shoot alone, are legally responsible for each bullet they discharge and have the responsibility of proving their actions were proportionate.

Their actions are subject to human rights considerations, specifically the right to life in the Human Rights Act 1998 and the European Convention on Human Rights. This means that the use of lethal force will only be justified where it is shown to be absolutely necessary.

A statement released by the IPCC about today's shooting said: "IPCC investigators are also attending post incident procedures where the officers involved are expected to provide their accounts in connection with the incident.

"The IPCC will oversee the procedure where any police firearms involved will be examined to determine whether they were discharged and, if so, how many times."

The question of whether the degree of force used is reasonable or not is often a controversial one and is decided on the circumstances the officer believed themselves to be in – not the actual circumstances.

In the case of today’s shootings, the officers will be found to have used reasonable force if they thought themselves in immediate danger.

Generally speaking, official policy says firearms officers “shoot to incapacitate”. Targeting the centre of the chest as the quickest way to neutralise a suspect, even though it is likely to kill.

When police can use force

The College of Policing states, under its ‘Armed Policing’ guidelines: “When police are required to use force to achieve a lawful objective (eg, making a lawful arrest, acting in self-defence or protecting others) all force used must be reasonable in the circumstances.

“If the force used is not reasonable and proportionate, the officer is open to criminal or misconduct proceedings. It may also constitute a violation of the human rights of the person against whom the force was used.

“Each authorised firearms officer is individually responsible and accountable for their decisions and actions, nothing can absolve them from such responsibility and accountability.

“This includes decisions to refrain from using force as well as any decisive action taken, including the use of force, the use of a firearm and the use of a less lethal weapon.

“AFOs are answerable, ultimately, to the law in the courts. They must be in a position to justify their decisions and actions based on their honestly held belief as to the circumstances that existed at the time, and their professional and legal responsibilities.”