A firearms officer who raised his gun in the same second a colleague shot Chris Kaba during a police vehicle stop told jurors he feared he would be run over and killed.

The Metropolitan Police officer, referred to as DS87, was standing beside Martyn Blake when he opened fire on the unarmed driver of a suspect Audi car on the evening of September 5 2022.

The blue Audi had been used as the “getaway” car after shots were fired outside a school in Brixton the night before – and neither shotgun nor suspects had been found, jurors were told.

DS87 was asked about his thoughts as Blake opened fire, hitting Mr Kaba in the forehead through the front windscreen.

He said: “I have got no doubt in my mind, given a moment longer the Audi would have come forward and I would have gone under.

“I felt in fear for my life. Had the actions not been taken at that point, I would have died or been injured.”

DS87 was the Operational Firearms Commander in charge of initiating the enforced stop with extraction of the Audi in Streatham, south London.

He was one of three occupants of the “Alpha” armed response vehicle (ARV) that had spotted the Audi in Camberwell and began to follow, joined by two more ARVs by the time it was stopped.

He noticed the driver was alone in the vehicle and that he took an “unnatural” route suggesting he was aware that he was being followed.

The officer said he took note of risks such as members of the public and speed bumps on the road before ordering the “in line” stop in Kirstall Gardens, Streatham.

DS87 gave a commentary on his body-worn video footage which showed him exiting the unmarked police car behind the Audi.

He said he heard “revving” and “crunching” sounds and the smell of burnt rubber as the suspect vehicle moved forwards and backwards to “ram its way out”.

The officer was heard on the footage to shout “armed police, show me your hands, show me your hands” as he approached the front passenger side door, which he found locked.

He told jurors: “At the point of contact on arriving at the passenger door it was clear the vehicle was trying to make off.

“The vehicle only ever makes a reverse in order to have more power to go forward.”

He hit the passenger side window with the barrel of his gun in an attempt to break it and attract the driver’s attention, jurors heard.

He said: “It is not something you would use in a normal stop. This is the first instance a vehicle has tried to ram its way out.

“When police shout ‘stop police’, we usually have compliance. It’s not something I have experienced before.

“Me striking the windscreen was one way to get a reaction from the driver to see if they would stop, show my presence, to see if they would stop but remove the window.”

Breaking the window would give him “less lethal options” including using a taser and would help him communicate with the driver, the officer said.

In the footage, Mr Kaba could be seen hunched down in the driver’s seat with his right hand on the wheel and left hand covering his head.

The witness then ran around to the front and was standing beside Blake as he opened fire.

DS87 said he raised his semi-automatic carbine at “the same second”, but fractionally behind Blake.

Shouts of “shot, shots fired, shots fired” were heard on the body-worn video immediately afterwards.

Defence barrister Patrick Gibbs KC asked whether he had been thinking of backing away from the Audi in that moment.

The officer replied: “Yes, so my initial thought was to move around to the front of the vehicle to contain it.

“My next thought was to close down the vehicle, the use of the firearm, make the person surrender and not cause a threat to officers.

“Closing down the vehicle as best as I could. As soon as I came around and saw the vehicle was reversing I knew it was going to come forward. I was in a position I didn’t want to be in.

“I didn’t want to land in that position but I guess training takes over and the priority was to contain the vehicle.”

He added: “I had never experienced that level of threat from someone, certainly when pointing a firearm.

“To have no regard for members of the public or the police in the vicinity. It was clear to me even if I have taken a shot, the vehicle would have moved forward.

“It was instinct or a way of survival to begin to withdraw and get away from the vehicle. It happened so quickly.”

The officer told jurors that after he raised his gun with torch on, he noticed the driver was still and had “minimal” blood on his forehead.

He said: “I worked my way round to the left. I see the driver. I can see the bleeding. It is at that point I assessed the driver has been shot in the head.”

“Once I realised he has been injured, no longer poses a threat, I shouted to get him out of the vehicle. First aid and saving life was a priority. He was still within the driver’s seat. Being at front I believe I had a better overview of what was going on in the Audi hence I shouted ‘get him out’ to give him first aid.”

The officer gave evidence from behind a screen as Mr Kaba’s family sat in the well of the court just metres away.

Blake, 40, has denied Mr Kaba’s murder at the Old Bailey and the trial was adjourned until Monday.