Firearms officers are "understandably anxious" after a force marksman was charged with the murder of Chris Kaba, the Metropolitan Police Commissioner has said.
The officer accused of his murder, named only as NX121 after an anonymity order was granted by a district judge, appeared at Westminster Magistrates' Court and the Old Bailey on Thursday.
Sir Mark Rowley said he has met with 70 firearms officers who operate all across London after the murder charge.
He said he understands "why many of them are reflecting on the potential price of such weighty responsibilities".
The Met Commissioner also said officers were anxious "as they consider how others may assess their split-second decisions years after the event, with the luxury of as much time as they want to do this".
In a statement, Sir Mark said: "This week a Met firearms officer was charged with murder following the fatal shooting of Chris Kaba.
"I cannot talk about that case specifically as proceedings are very much active and I am mindful of the impact this is having on all those directly affected.
"On Thursday I met with 70 firearms officers to reflect on the events of this week.
"Like me, they understand the importance of transparency and accountability, and recognise the awful effect on everybody involved on the very rare occasions when lethal force is used by the police.
"That impact is exacerbated by the very slow speed that investigations, trials, inquests and hearings run at, meaning the lives of everyone affected are on hold for many years."
Sir Mark continued: "They were understandably anxious as they consider how others may assess their split-second decisions years after the event, with the luxury of as much time as they want to do this, and the effect this can have on them and their families.
"As I continue my work today, our firearms officers are on patrol deployed on proactive crime and counter-terrorism operations as they are every day.
"They are not only prepared to confront the armed and dangerous to protect London's communities but they do so recognising the uniquely intense and lengthy personal accountability they will face for their split-second operational decisions.
"Indeed, I understand why many of them are reflecting on the potential price of such weighty responsibilities.
"Bravery comes in many forms.
"When officers have the levels of uncertainty and worry I saw in my colleagues today, simply going in and doing their jobs not knowing what incidents are ahead of them is courageous."
In the moments before the shooting, Mr Kaba had driven into Kirkstall Gardens and collided with a marked police car.
The officer fired one shot and hit Mr Kaba in the head.
Recorder of London Mark Lucraft KC told the marksman that a plea and trial preparation hearing will be listed for 1 December, with a possible trial date of 9 September next year.
NX121 was released on bail on the conditions that he lives at a named address, surrenders his passport and does not apply for international travel documents.