Police treated the attack as "Islamist-related terrorism". Masood reportedly said in a final text message that he was waging jihad in revenge for Western military action in Muslim countries in the Middle East. Amaq News Agency, which is linked to Islamic State, said the attacker answered the group's calls to target citizens of states that are fighting against it, though the claim was questioned by the UK police and government. Police have found no link with a terrorist organisation and believe Masood acted alone.
The attack started when Khalid Masood mounted the kerb. He turned the car toward the pavement and crashed into Kurt Cochran and Melissa Cochran. Before the collision, Kurt had pushed Melissa out of the way and took the full hit. Kurt flew off the bridge and landed on the embankment below falling 5.12 metres (16 ft 10 in) down, fatally injured. Melissa survived the attack and was wounded after being pushed by the car into a kiosk. The attack continued as Masood drove down the pavement and moved 22 metres (72 ft 2 in) forward. Masood then hit Leslie Rhodes and dragged him underneath the vehicle for 33 metres (108 ft 3 in), whilst moving back to the road to avoid a traffic sign. Masood then mounted the pavement again and hit Aysha Frade. Aysha Frade somersaulted approx. 17.1 metres (56 ft 1 in) and landed in the bus lane, underneath the rear of a bus. The bus was moving during the time and ran over her. The vehicle moved towards the road again, with the driver’s side on the road while the passenger’s side was on the pavement.
The car struck multiple people before hitting Andreea Cristea. Before being hit, Cristea had been out with her boyfriend and had taken a photo of the car. Cristea, a Romanian tourist, was thrown by the car's impact over the parapet of the bridge into the River Thames below. Having been knocked unconscious and sustained severe injuries from the fall, she was later rescued by the crew of a river cruise and brought aboard a London Fire Brigade boat. She later died in hospital from her injuries.
After striking Andreea, the car went back into the roadway, before mounting the pavement again, and drove past the traffic lights for a very short distance. The vehicle then went back to the road and crashed into railings on Bridge Street at the north perimeter of the Palace of Westminster, trying to aim at a group of pedestrians in the area.
Masood, wearing black clothes and wielding a knife in each hand, got out of the car and ran around the corner into Parliament Square and through the open Carriage Gates where he got into a struggle with an unarmed police officer, PCKeith Palmer. Masood pushed PC Keith Palmer back against the barrier wall, making Palmer trip. While Palmer was lying against the wall, Masood fatally stabbed Palmer. An armed police officer (believed to have been the Metropolitan Police close protection officer for the then Secretary of State for DefenceMichael Fallon) witnessed the stabbing, ran towards the scene and shot Masood dead. During that time, Palmer managed to go past the vehicle barrier and tried to go towards the area where the armed officers who had shot Masood were, until he eventually collapsed. The entire attack, from start to finish, lasted 82 seconds.
Despite attempts to resuscitate him, Masood died at the scene having been hit by all 3 shots fired by the police. The first bullet, which struck his upper torso, was believed to be the cause of death; he was pronounced dead at 15:35 at hospital. Police colleagues and passers-by, including MP Tobias Ellwood (the Foreign Minister for the Middle East and Africa) and paramedics, attempted to revive PC Palmer, also without success. Police later confirmed that PC Palmer had been wearing a protective vest, which did not appear to have been punctured in the attack.
The hearse carrying PC Keith Palmer en route to Southwark Cathedral
Six people, including the attacker, died as a result of the incident, and around 50 others were injured, some of them severely. Of the five people killed by the attacker, three were British nationals. One of the dead was a female teacher who was believed to have been walking along the bridge to pick up her children from school. A tourist from the United States also died; he was visiting London from Utah to celebrate his 25th anniversary with his wife, who was among the injured. The police officer killed was PC Keith Palmer, 48, an unarmed police officer who was on duty with the Parliamentary and Diplomatic Protection command. Palmer had 15 years of experience in the Metropolitan Police Service.
The fourth victim was a 75-year-old man from Clapham in south-west London, who was hit by the car and later died in hospital after his life support was switched off. A fifth victim, a 31-year-old female tourist from Romania, fell into the Thames during the attack; she died in hospital as a result of her injuries on 6 April after her life support was withdrawn. Her Romanian boyfriend, who had planned to propose marriage during their trip to London, was also injured during the attack.
The attacker was identified by the Metropolitan Police as 52-year-old Briton Khalid Masood. He was born Adrian Russell Elms, but later changed the name to Adrian Russell Ajao when he took the name of his stepfather. He changed his name to Khalid Masood after he converted to Islam. Police said he also used several other aliases, including Khalid Choudry.
Born in Kent, Masood was brought up in Rye, East Sussex, and later attended secondary school in Tunbridge Wells in Kent. Most recently he was living in the West Midlands. When he was 16, he dropped out of school and by 18 he was described as a heavy cocaine user. In 2000, he was sentenced to two years in prison for grievous bodily harm after a knife attack in a public house in Northiam in Sussex. In 2003, he was sentenced to a further six months in prison for possession of an offensive weapon following another knife attack in Eastbourne in Sussex. As well as these two prison terms, Masood had convictions for public order offences going back to 1983.
A British newspaper obtained a CV of Masood's in which he described himself as having taught English in Saudi Arabia from November 2005 to November 2006, and again from April 2008 to April 2009. After this, according to the CV he returned to the United Kingdom and worked at a TEFL college in Luton. In early March 2015, he made a brief trip to Saudi Arabia on an Umrah visa, normally issued to those making a pilgrimage to Mecca. During his time in Saudi Arabia he was not recorded as having a criminal record there.
In 2010, Masood was described as a "peripheral figure" in an MI5 investigation of a group of Islamists later convicted of plotting to bomb a Territorial Army base in Luton. Following a risk assessment, MI5 decided he did not pose a threat. The Metropolitan Police said he was not the subject of any current investigations and there was no prior intelligence about his intent to mount a terrorist attack. He had not been convicted of any terrorism offences.
Farasat Latif, director of the language school in Luton where Masood taught between 2010 and 2012, told The Guardian that when Masood lived in Luton he was apolitical and not aligned with the younger and predominantly Asian local radical Islamist group Al-Muhajiroun. Although aware of violence in Masood's past, Latif had only seen him become angry once, when Masood learnt of plans for a march by the English Defence League through Luton. Between 2012 and 2016, Masood appeared in MI5 investigations as a contact of individuals linked to Al-Muhajiroun.
Three days before the attack, Masood carried out reconnaissance of Westminster Bridge in person and online. Masood spent the night before the attack at the Preston Park Hotel in Brighton in Sussex and was described as "laughing and joking" by the manager there. At a pre-inquest hearing, it was revealed that he had used anabolic steroids shortly before the terrorist attack.
Masood's profile was atypical in that most jihadi terrorists are under 30, while he was 52.
On 22 March, the day of the attack, the Metropolitan Police said it believed the attack was inspired by "international terrorism" and that they were working under the assumption that it was "Islamist-related terrorism". On 23 March, the Islamic State-associated Amaq News Agency announced that the attacker was "a soldier of the Islamic State, executing the operation in response to calls to target citizens of coalition nations". The Home Secretary, Amber Rudd, cast doubts on this claim. Analysts monitoring Islamic State online said the claim appeared to be an effort to mask its losses in Iraq and Syria, adding that the lack of biographical information on the attacker and lack of specifics about the attack suggested it was not directly involved.
Describing Masood as a "terrorist", the Metropolitan Police said it was investigating whether he was a lone actor inspired by terrorist propaganda or was being directed by others. On 25 March Neil Basu, Deputy Assistant Commissioner of the Metropolitan Police and Senior National Coordinator for UK Counter-Terrorism Policing, announced that investigators believed Masood acted alone. On 27 March, Basu announced that Masood clearly had an interest in jihad, that his methods echoed the rhetoric of Islamic State leaders and that investigators have found no evidence he was linked with it or al-Qaeda.
The security services later recovered the last WhatsApp message sent by Masood shortly before his attack. In it, Masood reportedly said he was waging jihad in revenge for Western military action in Muslim countries of the Middle East. He had written a document named "Jihad in the Quran and Sunnah", with his photograph on the front page and multiple extracts from the Quran that could be seen as supportive of jihad and martyrdom. He sent this document to numerous contacts a few minutes before the attack.
Some early reports gave descriptions of two supposed attackers, one described as a "bald white man" and another as a "black man with goatee beard". On the morning after the attack, however, Mark Rowley, the Metropolitan Police's Assistant Commissioner for Specialist Operations, stated that the police believed the attacker acted alone.Abu Izzadeen was also erroneously identified as the attacker on social media, Channel 4 News and The Independent shortly after the attack, although Izzadeen was actually in prison at the time. In April 2017, OFCOM announced an investigation into the Channel 4 News naming of Izzadeen.
Police and media outside the Hagley Road premises that were raided on 22 March, seen on the morning following the raid
At 23:00 on 22 March, West Midlands Police raided a flat in Hagley Road, Birmingham. By the morning of 23 March, six locations in East London and Birmingham had been raided resulting in the arrests of eight people on suspicion of preparing terrorist acts. Officials also carried out searches in London, Brighton and Carmarthenshire. The investigation was named Operation Classific. By 24 March, three further arrests had taken place, two men overnight in the West Midlands and North West England and a woman during the day in Manchester. A woman, arrested earlier in East London, was released on bail. Later on 24 March, seven of those initially arrested were released without further action and the woman arrested in Manchester was released on bail.
By 25 March, only one man from Birmingham remained in custody and the woman on bail from East London had been removed from police enquiries. Up to that point in the investigation, 2,700 items had been seized and 3,500 witnesses had been contacted. A further arrest was made in Birmingham on 26 March. By 1 April, all 12 suspects arrested after the attack had been released without charge.
Inquests for the dead victims were opened and adjourned on 29 March 2017, and into Masood's death the following day, both under the Senior Coroner for Westminster, Dr Fiona Wilcox.
On 12 October 2018, the jury at the inquest into Masood's death, held under the direction of the chief coroner of England and Wales, found that Masood had been lawfully killed by a minister's close protection officer identified only as SA74. Two plain-clothed armed officers from the Royalty and Specialist Protection branch of the Metropolitan Police were awaiting their principle when they became aware of the ongoing attack. SA74 recounted to the court how Masood had ignored shouted warnings and how he had opened fire in response to Masood running towards him while brandishing two bloodied knives.
Floral tributes left in Parliament Square following the attack
Reactions to the attack expressed shock and outrage, and characterised it as an attack against liberty, freedom of speech, and democracy.
Both the House of Commons and the House of Lords resumed their normal functions on 23 March, the day after the attack. A one-minute silence in honour of the dead was observed in Parliament, and by London's emergency services, at 09:33. The time was selected to coincide with the start of the day's official parliamentary business. In the morning session of parliament, Prime Minister Theresa May said that, "Yesterday an act of terrorism tried to silence our democracy, but today we meet as normal ... to deliver a simple message: We are not afraid and our resolve will never waver in the face of terrorism." In a later statement following the June 2017 London attack, May stated that all three recent attacks were "bound together by the single evil ideology of Islamic extremism". The Labour leader Jeremy Corbyn, the Leader of the Opposition, described the attack as "an appalling atrocity". The speakers of both Houses of Parliament jointly offered sympathy to those affected, and thanked the emergency services. The Scottish Parliament suspended the day's proceedings, including a debate on a second independence referendum. Some MSPs who opposed the decision to suspend parliament said that doing so was "giving in to terrorism".
The Metropolitan Police honoured PC Palmer by retiring his shoulder number 4157U; Charlton Athletic F.C. announced that his season ticket seat at the Valley would not be occupied at the club's next home game, but would instead have a club scarf placed over it as a mark of respect. A JustGiving fund was set up, with the target of raising £100,000 for his family, a goal attained in less than 24 hours. A group called "Muslims United for London" also raised over £29,000 to support victims and victims' families, releasing a statement saying, "The British Muslim community stands with the community during these difficult times". Home Secretary Amber Rudd announced that PC Palmer would be remembered at the National Memorial Arboretum's UK Police Memorial in Staffordshire.
On 26 March, in an event organised by Women's March on London, roughly 100 women, including many Muslims, joined hands to form a chain along Westminster Bridge and stood in silence for five minutes to pay tribute to the victims of the attack. Amber Rudd appeared on BBC's The Andrew Marr Show to call for government backdoor access to encrypted messaging services like WhatsApp, which Masood used to send a message shortly before the attack. She announced a meeting with similar technology industry leaders for 30 March, where she would persuade them to voluntarily co-operate with the government. She refused to rule out passing new legislation to this end if the companies do not comply.
The BBC TV series Hospital was filming a routine meeting at St Mary's when the attack occurred; within minutes St Mary's declared a "major incident", one of several central London hospitals to do so. The cameras recorded the involvement of the emergency room and intensive care staff over the next few hours, and then followed the cases of three patients until their discharge. The hour-long episode was broadcast in June, resulting in "a powerful, moving portrait of a major trauma centre’s response to such an event, and of the brilliant human beings who work there."