It came as Suella Braverman gave her public backing to marksmen and women who have to make “split-second decisions” and “mustn’t fear ending up in the dock for carrying out their duties”.
In an open letter to the Home Secretary, Commissioner Sir Mark Rowley called for reform of the way police officers are held to account, particularly when they use force or undertake pursuits in the course of their duties.
Progress being made to deliver change in the Met was “undermined by a system not set up to help officers succeed”, he said citing policies of the Independent Office for Police Conduct and the Crown Prosecution Service.
Sir Mark told Braverman: “Officers need sufficient legal protection to enable them to do their job and keep the public safe, and the confidence that it will be applied consistently and without fear or favour.”
Father-to-be Mr Kaba, 24, was shot and killed in Streatham Hill last year.
The officer charged with his murder – identified only as NX121 – appeared at the Old Bailey on Thursday.
Scotland Yard requested military support for anti-terror duties if armed officers are unavailable.
A Met Police spokesperson said on Sunday: “The Ministry of Defence has agreed to a request to provide the Met with counterterrorism support should it be needed.
“This is a contingency option that would only be used in specific circumstances and where an appropriate policing response was not available.
“Armed forces personnel will not be used in a routine policing capacity. We will keep the need for the support under constant review.”
More than 100 firearms officers have handed in their permit to carry firearms as a result of the charge.
The Met said that officers were concerned that the charge “signals a shift in the way the decisions they take in the most challenging circumstances will be judged”.
Reacting to the reports, Ms Braverman wrote on X: “We depend on our brave firearms officers to protect us from the most dangerous and violent in society. In the interest of public safety they have to make split-second decisions under extraordinary pressures.
“They mustn’t fear ending up in the dock for carrying out their duties. Officers risking their lives to keep us safe have my full backing and I will do everything in my power to support them.
“That’s why I have launched a review to ensure they have the confidence to do their jobs while protecting us all.”
Senior officers, including Scotland Yard chief Sir Mark Rowley, have been meeting with firearms officers in recent days to reflect on the murder charge.
Mr Kaba died on September 5 last year from a single gunshot wound to the head.
The officer fired one shot that passed through the windscreen of the Audi that Mr Kaba was driving and hit him in the head.
A spokesman for the force said: “The Met has a significant firearms capability and we continue to have armed officers deployed in communities across London as well as at other sites including Parliament, diplomatic premises, airports etc.”
“Our priority is to keep the public safe. We are closely monitoring the situation and are exploring contingency options, should they be required.”
There are more than 3,000 firearms officers working across a number of units at the Met.
A Ministry of Defence spokesman said: “We have accepted a Military Aid to the Civil Authorities (MACA) request from the Home Office to provide routine counterterrorism contingency support to the Metropolitan Police, should it be needed.”
The army would only assist with specific tasks the police are unable to perform and would not perform any routine policing work, or have the power of arrest.