British police forensics officers work near a grey vehicle that crashed into the railings of the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
A police boat patrol on the River Thames, near to the Houses of Parliament in Westminster, central London on March 22, 2017, during an emergency incident. (Photo credit JOEL FORD/AFP/Getty Images)
Terror Incident Outisde Parliament
Police investigators seen on Westminster Bridge on March 22, 2017 in London, England. (Photo by Carl Court/Getty Images)
Terror Incident Outisde Parliament
British counter-terrorism police officers carry their weapons as they work on Westminster Bridge, adjacent to the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Members of the Ambulance and Fire Brigade emergency services stand alongside a stationary London bus as they work on Westminster Bridge, alongside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit NIKLAS HALLE'N/AFP/Getty Images)
Terror Incident Outisde Parliament
People look out from pods on The London Eye after it's service was suspended on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
A police sniffer dog works with members of the emergency services on Westminster Bridge, alonside the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Armed officers attend to the scene outside the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
Paramedics load a victim into the back of an ambulance as members of the emergency services work on Westminster Bridge, alongside the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit NIKLAS HALLE'N/AFP/Getty Images)
Terror Incident Outisde Parliament
Emergency services are seen on Westminster Bridge on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
Members of the emergency services work on Westminster Bridge, alongside the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit NIKLAS HALLE'N/AFP/Getty Images)
Terror Incident Outisde Parliament
Armed police officers man a security cordon as members of the emergency services work on Westminster Bridge, alonside the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Emergency services make their way down the river on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
Armed police officers stand guard, as forensics officers work around a grey vehicle that crashed into the railings of the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Armed police officers stand guard on the corner of Parliament Square, near the Houses of Parliament in central London on March 22, 2017, during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Forensics officers work at the scene of a terror incident outside the Houses of Parliament in central London on March 22, 2017. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
Terror Incident Outisde Parliament
Members of the public look on as roads are closed off by Police around Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
Emergency services make their way down Westminster Bridge towards the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
Armed officers attend to the scene outside the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Carl Court/Getty Images)
Terror Incident Outisde Parliament
An Air Ambulance at the scene by Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
Terror Incident Outisde Parliament
A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Carl Court/Getty Images)
Terror Incident Outisde Parliament
A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Carl Court/Getty Images)
Terror Incident Outisde Parliament
A police officer stands guard near Westminster Bridge and the Houses of Parliament on March 22, 2017 in London, England. (Photo by Jack Taylor/Getty Images)
'Terrorist Incident' Outside UK Parliament
Armed police officers stand guard near the Black Rod's Garden entrance of the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
Armed police officers stand guard inside a security cordon, outside of the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident.
(Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
An ambulance is driven through a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
People leave after being evacuated from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
London's air ambulance arrives at the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
Armed police officers guard at a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
A police officer stops traffic as the Jaguar car of British Prime Minister Theresa May (R) is driven away from the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
Armed police officers stand guard at a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
Armed police officers guard at a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
A police officer sets up a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
'Terrorist Incident' Outside UK Parliament
An armed police officer guards inside a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident. (Photo credit DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
The sun sets behind the Houses of Parliament in central London on March 22, 2017 as emergency services deal with the aftermath of a terror incident.
British police shot a suspected attacker outside the Houses of Parliament in London on Wednesday after an officer was stabbed in what police said was a "terrorist" incident. One woman has died and others have "catastrophic" injuries following a suspected terror attack outside the British parliament, local media reported on Wednesday citing a junior doctor. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
London Terror Attack
News reporters and Police are stationed outside Westminster Abbey next to the Houses of Parliament on March 22, 2017 in London, England. A police officer has been stabbed near to the British Parliament and the alleged assailant shot by armed police. Scotland Yard report they have been called to an incident on Westminster Bridge where several people have been injured by a car. (Photo by Jack Taylor/Getty Images)
London Terror Attack
Police boats patrol outside the Houses of Parliament after a terrorist attack on March 22, 2017 in London, England. Four people including a police officer and his attacker have been killed in two related incidents outside the Houses of Parliament and on Westminster Bridge in what Scotland Yard are treating as a terrorist incident. (Photo by Carl Court/Getty Images)
London Terror Attack
British police officers work on Westminster Bridge, adjacent to the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
Three people were killed and 20 injured in a "terrorist" attack outside the British parliament Wednesday when a man mowed down pedestrians, then stabbed a police officer before being shot dead. The car struck pedestrians on Westminster Bridge, a popular spot with tourists because of its views of Big Ben, before crashing into the railings outside the heavily guarded parliament building in the heart of the British capital. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
London Terror Attack
British police officers work on Westminster Bridge, adjacent to the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
Three people were killed and 20 injured in a "terrorist" attack outside the British parliament Wednesday when a man mowed down pedestrians, then stabbed a police officer before being shot dead. The car struck pedestrians on Westminster Bridge, a popular spot with tourists because of its views of Big Ben, before crashing into the railings outside the heavily guarded parliament building in the heart of the British capital. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
London Terror Attack
People leave after being evacuated from around the Houses of Parliament and Parliament Square in Westminster, central London on March 22, 2017 during an emergency incident.
Three people were killed and 20 injured in a "terrorist" attack outside the British parliament Wednesday when a man mowed down pedestrians, then stabbed a police officer before being shot dead. The car struck pedestrians on Westminster Bridge, a popular spot with tourists because of its views of Big Ben, before crashing into the railings outside the heavily guarded parliament building in the heart of the British capital. (Credit: DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
Emergency services' vehicles are pictured on Westminster Bridge, adjacent to the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
A police officer was among three killed Wednesday in a suspected terrorist attack outside Britain's parliament by an assailant who was then shot dead by armed police, Britain's top anti-terror officer said. Mark Rowley said the two other victims died on Westminster Bridge in London after the attacker mowed down pedestrians in a car, leaving at least 20 people injured in total. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
BRITAIN-POLITICS-INCIDENT-ATTACK
Ambulances are pictured outside St Thomas' Hospital in central London on March 22, 2017, in the aftermath of a terror incident at Parliament.
A police officer was among three killed Wednesday in a suspected terrorist attack outside Britain's parliament by an assailant who was then shot dead by armed police, Britain's top anti-terror officer said. Mark Rowley said the two other victims died on Westminster Bridge in London after the attacker mowed down pedestrians in a car, leaving at least 20 people injured in total. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
Suspected Terror Incident At the Houses of Parliament
An armed police officer stands guard outside the Ministry of Defence on March 22, 2017 in London, England. A police officer has been stabbed near to the British Parliament and the alleged assailant shot by armed police. Scotland Yard report they have been called to an incident on Westminster Bridge where several people have been injured by a car.(Photo by Jack Taylor/Getty Images)
Firearms Incident Takes Place Outside Parliament
A police officer at the scene of a terrorist attack in which a number of pedestrians were mowed down on Westminster Bridge on March 22, 2017 in London, England. Four people including a police officer and his attacker have been killed in two related incidents outside the Houses of Parliament and on Westminster Bridge in what Scotland Yard are treating as a terrorist incident. (Photo by Carl Court/Getty Images)
BRITAIN-POLITICS-INCIDENT-ATTACK
Members of the emergency services stand alongside a police forensics tent on the Albert Embankment footpath, opposite the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
A police officer was among three killed Wednesday in a suspected terrorist attack outside Britain's parliament by an assailant who was then shot dead by armed police, Britain's top anti-terror officer said. Mark Rowley said the two other victims died on Westminster Bridge in London after the attacker mowed down pedestrians in a car, leaving at least 20 people injured in total. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
London Terror Attack
Police officers block access to the southern entrance of Westminster Bridge on March 22, 2017 in London, England. Four people including a police officer and his attacker have been killed in two related incidents outside the Houses of Parliament and on Westminster Bridge in what Scotland Yard are treating as a terrorist incident. (Photo by Carl Court/Getty Images)
London Terror Attack
A Police boat patrols the river Thames by St Thomas' hospital and Westminster Bridge on March 22, 2017 in London, England. A police officer has been stabbed near to the British Parliament and the alleged assailant shot by armed police. Scotland Yard report they have been called to an incident on Westminster Bridge where several people have been injured by a car. (Photo by Jack Taylor/Getty Images)
London Terror Attack
A police Land Rover pulls a car transporter alongside the scene where a grey vehicle crashed into the railings of the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
At least three people were killed and 20 injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead. Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben. (Credit: DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
A police Land Rover pulls a car transporter alongside the scene where a grey vehicle crashed into the railings of the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
At least three people were killed and 20 injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead. Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben. (Credit: DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
British Police officers stand betwen the pods of the London Eye, during the evacuation of passengers, in central London on March 22, 2017, in the aftermath of a terror incident at the Houses of Parliament.
At least three people were killed and 20 injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead. Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben. (Credit: JOEL FORD/AFP/Getty Images)
London Terror Attack
CCTV cameras are pictured in front of the Elizabeth Tower at the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
At least three people were killed and 20 injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead. Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben. (Credit: DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
British police forensics officers work near a grey vehicle that crashed into the railings of the Houses of Parliament in Westminster, central London on March 22, 2017, in the aftermath of a terror incident.
At least three people were killed and 20 injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead. Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben. (Credit: DANIEL LEAL-OLIVAS/AFP/Getty Images)
London Terror Attack
People are seen inside the pods of the London Eye, opposite the Houses of Parliament in Westminster, central London on March 22, 2017 as emergency services deal with the aftermath of a terror incident at Parliament.
British police shot a suspected attacker outside the Houses of Parliament in London on Wednesday after an officer was stabbed in what police said was a "terrorist" incident. One woman has died and others have "catastrophic" injuries following a suspected terror attack outside the British parliament, local media reported on Wednesday citing a junior doctor. (Credit: NIKLAS HALLE'N/AFP/Getty Images)
