Sir David Amess MP killer: Suspect Ali Harbi Ali detained by police under Terrorism Act - he was known to MI5

Just over 32 hours after the fatal attack on Conservative MP Sir David Amess, Scotland Yard have named the suspect they believe to be responsible for his murder.

At around 8.30pm on Saturday, October 16, 25-year-old Ali Harbi Ali was named as the only suspect in the case of Mr Amess’ murder.

Detained under acts of terrorism

It is understood that Ali Harbi Ali has been detained at a London police station under section 41 of the Terrorism Act 2000.

It was confirmed in the hours after Mr Amess was stabbed to death at a Leigh-on-Sea Methodist church that the suspect was thought to have been motivated by Islamist extremism.

In a statement, Scotland Yard said: “On Saturday, detectives were granted a warrant of further detention at Westminster Magistrates’ Court, allowing them to keep the man in custody until October 22, when the warrant expires.

“As part of the fast-paced investigation, officers have attended three addresses in the London area and conducted searches. One of these searches has concluded and the others are ongoing. A post-mortem examination has taken place today (Saturday, 16 October).”

The suspect is believed to be of Somali heritage but is a British national.

The police are not looking for any other suspects at this time, it is believed that Mr Ali was a lone attacker.

Known to the counter-terrorism Prevent scheme

It is understood that Mr Ali was referred to the counter-terrorist Prevent scheme some years ago, but was never a formal subject of interest to MI5.

He was later discharged from the programme, which aims to prevent radicalisation of those who are targeted by extremist organisations to become terrorists.

The UK government’s 2011 Prevent Strategy states: “Experience tells us that the threat comes not just from foreign nationals but also from terrorists born and bred in Britain.

“It is therefore vital that our counter-terrorism strategy contains a plan to prevent radicalisation and stop would-be terrorists from committing mass murder.”

What happened to Sir David Amess MP?

Here is a timeline of events in the death of Conservative MP Sir David Amess.

October 15

Tory MP Sir David Amess is fatally stabbed at Belfairs Methodist Church in Leigh-on-Sea near Southend at about midday while attending a constituency surgery.

12.05pm: Essex Police receive reports of the incident. Officers arrive at the church shortly after and arrest a 25-year-old man.

2.58pm: Essex Police confirm a man died at the scene, they are not looking for anyone else in relation to the attack and a knife was recovered.

3.50pm: Flags are lowered to half mast outside Parliament as tributes flood in for the MP

3.55pm: Prime Minister Boris Johnson arrives back at Downing Street, he had been scheduled to attend media opportunities in Bristol but the Cabinet meeting was cancelled

4.07pm: Sir Lindsay Hoyle, Speaker of the House of Commons, says in a statement he is “shocked and deeply distressed by the killing of Sir David Amess”, adding: “In the coming days we will need to discuss and examine MPs’ security and any measures to be taken”.

4.54pm: The first floral tribute is laid at a police cordon following Sir David’s death. The tribute, from a young woman, reads: “A silent thought, a quiet prayer, for a special person in God’s care. May you rest in peace.”

5.02pm: Sir David’s death is confirmed by Essex Police.

5.12pm: Speaking to media, Mr Johnson says “all our hearts are full of shock and sadness” at Sir David’s passing, adding that the long-serving MP was “one of the kindest, nicest, most gentle people in politics”.

5.17pm: Writing on Twitter, Home Secretary Priti Patel says questions are “rightly being asked” about the safety of MPs and she will “provide updates in due course”.

5.31pm: Labour leader Sir Keir Starmer issues a statement, calling it a “dark and shocking day”.

He says: “Let us come together in response to these horrendous events. We will show once more that violence, intimidation and threats to our democracy will never prevail over the tireless commitment of public servants simply doing their jobs.”

6pm: Around 80 people attend a vigil in memory of Sir David at St Peter’s Church, Eastwood Lane.

6.26pm: Commons Speaker Sir Lindsay Hoyle says there will be a review of MPs’ security following the death, but he cautions there must be no “knee jerk reaction”.

6.29pm: In a statement at Southend Police Station, Essex Police chief constable Ben-Julian Harrington says the investigation into Sir David’s death will be led by counter-terrorism officers.

7.01pm: A Home Office spokesman says the Home Secretary has asked all police forces to review security arrangements for MPs “with immediate effect”.

8.50pm: Official sources report the suspect is believed to be a British national with Somali heritage.

11.08pm: Sir Lindsay says police are contacting all MPs to check on their security.

October 16

12.13am: The fatal stabbing of Sir David is confirmed as a terrorist incident by the Metropolitan Police, with the investigation being led by counter-terrorism officers.

The force adds officers are carrying out searches at two addresses in the London area as part of their investigation.

9.10am: The Prime Minister, Labour leader and Home Secretary arrive at Leigh-on-Sea to pay tribute to Sir David, with Mr Johnson laying a wreath at the front of Belfairs Methodist Church.

10.12am: A National Police Chiefs’ Council spokesman announces every UK MP will be contacted by Operation Bridger, a nationwide police protective security operation established in 2016, to discuss their security arrangements.

10.37am: Speaking at Southend Police Station, the Home Secretary says a balance could be found between the democratic process and the security of MPs.

8.48pm: The name the police have for the suspect is Ali Harbi Ali, the PA news agency understands.

9.05pm: Scotland Yard says detectives have been granted a warrant of further detention at Westminster Magistrates’ Court which allows them to hold the suspect until October 22.