Murder of Sir David Amess MP: Terrorism Post-Incident Report
On 15 October 2021, Sir David Amess MP, a British Conservative politician, was stabbed and killed in a premeditated attack at a constituency surgery in Leigh-on-Sea.
When: 12.05 BST, 15 October 2021
Where: Leigh-on-Sea, Essex, United Kingdom
Who: Ali Harbi Ali, 25-year-old Somali-Briton (suspected Islamist extremist)
What: Bladed weapon attack against an elected representative
Deaths: 1
Injuries: 0
Type: Probable Islamist terrorist low complexity attack
Intelligence Cut Off Date: 23:59hrs  20 Oct 2021
We have been the UK’s leading terrorism reinsurer for over a quarter of a century. In that time we have developed a great deal of trust as globally renowned specialists in our field. Our team of experts combine their knowledge and experience with that of Government agencies, academia, risk professionals and the insurance industry – we call this our SOLUTIONS division.


On 15 October 2021, Sir David Amess MP, a British Conservative politician, was stabbed and killed in a premeditated attack at a constituency surgery in Leigh-on-Sea. Police subsequently stated the attack was a terrorist incident, and that a 25-year-old Briton of Somali heritage, named as Ali Harbi Ali, had been detained on suspicion of murder and terror offences.

Amess was holding a planned constituency surgery at in Belfairs Methodist Church Hall in Leigh-on-Sea. At 12:05, after speaking with constituents, Amess was approached by Ali who then stabbed him multiple times. Ali reportedly did not attempt to leave the building or attack anyone else present. He was arrested by responding police officers shortly afterwards, having offered no resistance. Despite the provision of first aid, Amess was too badly injured to be airlifted to hospital. He died of his wounds around 15:00.

Ali was initially arrested for murder and held at a police station in Essex. The Metropolitan Police subsequently announced that the fatal stabbing was being declared a terrorist incident, and that Counter Terrorism Police (CTP) were now leading the investigation. Ali was further arrested for offences under the Terrorism Act 2001 and remains in custody in London.

On 17 October, police searched several addresses in London in connection with the attack. While it appears Ali acted alone, police are investigating his links with Islamist extremism. Home Secretary Priti Patel ordered all police forces to review the security arrangements for Members of Parliament (MP).

Lethal terrorist attacks against police, military and government targets in Western Europe (2000-2020)
Lethal terrorist attacks on police, military and government targets in Western Europe (2000-2020)
Terrorist attacks against police and military government targets in Western Europe declined in the early part of the millenium as separatist-nationalist movements like ETA and the IRA demobilised. There was a significant rise from 2014 onwards as Daesh directed and inspired terrorists began targeting symbols of government authority, particularly police officers, but also politicians, civil servants and members of the judiciary.
Source: Global Terrorism Database, Maryland University


While police have not confirmed the attacker’s motives, they are treating the attack as a terrorist incident and are investigating Ali’s links to Islamist extremism. The stabbing is consistent with Islamist extremist attack methodologies and echoes historic Islamist attacks against MPs and other symbolic figures, including government employees, members of the Armed Forces, police, and judiciary, as well as journalists, artists, and writers critical of Islam.

While Islamist extremists in the UK typically attempt to carry out mass casualty attacks, often targeting members of the public indiscriminately, targeted attacks are both promoted and celebrated in extremist literature. In May 2010, Islamist extremist Roshonara Choudhary stabbed Stephen Timms MP with a kitchen knife at a constituency surgery in Beckton, severely injuring the parliamentarian and killing his aide. MPs have also been historically targeted by both right-wing extremists and Violent Dissident Republicans (see timeline).

Timeline of terrorist attacks on British MPs.
Timeline of terrorist attacks on British MPs.

There are conflicting reports as to whether Amess was specifically selected as a target by Ali for his Catholic faith, his conservative politics, or even his involvement with the Qatari government (where Ali’s father was a Somali diplomatic representative). Despite initial reports that Ali had booked a meeting with Amess, it appears that Ali was not known to Amess . It is likely he chose to attack Amess primarily because he was a MP (and therefore a symbolic target), rather than for any personal reason.

Press reports indicate that, having stabbed Amess multiple times, Ali discarded his knife and waited for police to arrive. Most recent Islamist attacks in the UK have seen attackers carry on indiscriminately targeting members of the public until stopped. This tactic is frequently employed to achieve ‘martyrdom’ (i.e., be killed by responding officers). However, not all Islamist extremist attacks result in indiscriminate violence; in 2013, two Islamist extremists murdered off-duty soldier Lee Rigby in Woolwich, before conversing with members of the public until armed police arrived. It is unclear if Ali had planned to be arrested as part of a wider strategy to gain public attention. Regardless, it appears he did not attempt to attack anyone other than Amess.

Following the attack, Home Secretary Priti Patel ordered police to review security arrangements for MPs. In the wake of the 2016 murder of Jo Cox MP by a right-wing extremist, police and parliamentary authorities implemented ‘Operation Bridger’ aimed at providing MPs with advice, guidance, and funding for standardised security measures. Many MPs are understood to have had protective security measures like panic alarms and toughened glass installed at their homes as part of the operation. The Home Secretary declared on 20th October that the Joint Terrorism Assessment Centre (JTAC) assessed that the threat to MPs had been raised to “Substantial” which is the same as the national threat level.

However, more is needed to address the vulnerability of MPs while conducting constituency surgeries. While MPs are being contacted by local police forces to identify their security concerns, several measures to improve the security of parliamentarians have been discussed. Tobias Ellwood MP publicly called for a ‘pause’ in face-to-face meetings with constituents due to the attack. However, MPs must balance the imperative for personal security with the need to be accessible to their constituents, something that those reviewing current security arrangements will be cognizant of.

Press reporting has highlighted that Ali was reportedly referred to ‘Prevent’, the government’s counter-radicalisation programme ‘several years ago’. It is presently unclear precisely why and when he was referred or by whom. Referrals are typically made by members of the public with concerns that an individual may be vulnerable to radicalisation. It is also unclear if Ali received, through the Prevent programme, ‘Channel’ support which aims to mitigate the risk of vulnerable individuals being drawn into criminal terrorist-related activity. This is distinct from the process for those who are assessed to present a ‘terrorism risk’ who are managed by the police and security services.

Lethal terrorist attacks on police, military and government targets in Western Europe (2000-2020)
Lethal terrorist attacks on police, military and government targets in Western Europe (2000-2020)
There have been more than 70 lethal terrorist attacks against police, military and government targets in Western Europe since 2000. Almost half of these targeted police officers. Politicians and party political activists were the second most targeted subcategory, with a total of 13 lethal attacks since 2000.
Source: Global Terrorism Database, Maryland University

Ali was apparently not known to MI5 as a ‘subject of interest’ (SOI) (subject of a current or historic counter-terrorism investigation). While the Prevent referral suggests a historic interest by Ali in Islamist extremism, there was likely insufficient evidence that he posed a credible threat to warrant further investigation by the police and MI5. There are currently around 3,000 SOIs and a further 20,000 former SOIs (for comparison, there were over 6,000 Prevent referrals in 2020 alone).

The involvement in several recent attacks of individuals who were SOIs or had been through the Prevent programme has resulted in considerable scrutiny of both Prevent and MI5’s handling of terror suspects. In practice, MI5 and CTP have limited resources and are obliged to allocate them based on the threat specific individuals are assessed to pose. Sometimes such assessments are shown to be flawed (as was the case with the 2017 Manchester Arena bomber). However, these are exceptions and the failure to prevent violence by those known to the security services is typically caused by a range of factors largely beyond their control, including the immense difficulty of preventing low-complexity attacks carried out with minimal preparation or planning.

Equally, participation in Prevent is voluntary, and the programme aims to disengage individuals from extremism before they become involved in criminal terrorist activity. Significant changes to the Prevent programme are likely to face legal obstacles and resistance from those who see it as inherently discriminatory. Increasing the involvement of the police and MI5 in managing individuals referred to Prevent ultimately may prove counterproductive. Nonetheless, a review into the efficacy of the current Prevent programme is a realistic possibility.

Notwithstanding the historic Prevent referral, press reporting indicated that Ali had extensively consumed extremist media during ‘lockdowns’ imposed in response to the Covid-19 pandemic, which may have precipitated his decision to plan an attack. Specifically, Ali was said to have become an avid follower of the high-profile Islamist agitator Anjem Choudhary, who is currently in prison on terror offences. The counter-terrorism community has publicly expressed concerns about a possible correlation between lockdowns and increased rates of radicalisation.

There is a realistic possibility that the UK is starting to experience the delayed effects of this dynamic, with individuals radicalised during the lockdowns beginning to plan and carry out attacks. It remains to be seen whether further attacks by such individuals materialise in the near-term, however, this is a realistic possibility. Wider social and geopolitical developments also point to a likely rise in the long-term rate of radicalisation and consequent attack planning. While a move to more sophisticated attack methodologies by UK-based extremists is unlikely, further low complexity attacks against unprotected targets are likely.

For any further questions about this blog, please contact the Pool Re SOLUTIONS Team at

To explore more resources from our Pool Re SOLUTIONS team, please click here.

Related Posts

Privacy Preferences
When you visit our website, it may store information through your browser from specific services, usually in form of cookies. Here you can change your privacy preferences. Please note that blocking some types of cookies may impact your experience on our website and the services we offer.