Here is a recap of everything we know so far.
The crash
Emergency services were called to a two-vehicle collision near the cemetery gates in London Road at around 8.25pm on Sunday.
It was reported that a man was seen leaving the collision holding what was described as a handgun.
The scene of the initial collision (Image: East Anglia News Service)
When officers arrived, one of the cars – a Mercedes van – was badly damaged, the airbag had gone off, and there was no one in the car.
The other car – a Honda Jazz – was damaged on one side.
The driver of the Honda suffered minor injuries and declined medical treatment in hospital.
Police tape left at the scene near the cemetery gates (Image: East Anglia News Service)
The shooting
Police received several reports from members of the public in the area that they had seen a man carrying a black handgun on London Road heading towards Sainsbury’s.
He was then seen on the southbound carriageway of the A11, near the Brandon Road roundabout, walking in a northbound direction.
Armed response officers were deployed to the A11.
The man was approached by officers and, a short time later, shot by police from a short distance away.
Despite the efforts of emergency services, he was pronounced dead at the scene.
He was pronounced dead at the scene (Image: East Anglia News Service)
A formal identification is yet to be confirmed, but it is understood that the man who died was in his 60s.
His next of kin has been informed of his death.
Following standard procedure, Norfolk Constabulary has referred itself to the Independent Office for Police Conduct (IOPC).
Deputy Chief Constable Dave Marshall said: “This is a very serious matter, sadly someone has lost their life, and I understand people will want to know what happened.
“However, there is a duty on this organisation, my colleagues and I, to protect the integrity and independence of the IOPC investigation so it can progress and make its own assessment of what happened.
“We are cooperating fully with the IOPC investigation and are in the process of handing over all body-worn video footage, 999 calls and drone footage so this can be thoroughly investigated, and to ensure full transparency.”
It happened on the stretch adjacent to the Forest Retail Park (Image: East Anglia News Service)
The investigation
A spokesman for the IOPC said: “At this early stage, we have established via police call logs that Norfolk Constabulary officers responded to a report of a collision involving two vehicles in London Road shortly before 8.30pm.
“Armed officers responded after it was reported that a man was seen leaving the collision scene holding what was described to be a handgun.
“We can confirm that two shots were fired by police shortly before 9pm.
Forensics teams on the A11 on Monday (Image: East Anglia News Service)
“First aid was provided at the scene, however the man was sadly declared deceased shortly before 10.15pm.
“We were notified by the force shortly before 9.40pm and declared an independent investigation.
“We have sent investigators to attend the police post-incident procedure to begin gathering evidence, including obtaining initial accounts from the officers involved, police logs, and securing police body worn video footage.
“What appears to be a non-police issue firearm has been recovered from the scene.”
Police blocking the A11 on Monday morning (Image: East Anglia News Service)
IOPC director Amanda Rowe added: “Fatal police shootings are rare, however when they do occur it’s essential that an independent investigation is carried out into the actions and decision-making of the officers involved.
“Our investigation is in its initial stages and we are in the process of obtaining and reviewing evidence as we begin to piece together the circumstances surrounding this incident.
“Our thoughts are with the man’s family and everyone affected by this incident. We will be making contact with the man’s family in due course to explain our role and the next steps.”
The road closure
A drone image of the investigation (Image: East Anglia News Service)
The A11 was closed in both directions between the Thetford Ranges roundabout and the Brandon Road roundabout.
The northbound carriageway reopened at around 2.45pm on Monday.
One lane of the southbound carriageway reopened at around 7.45pm, but the other lane remains closed for investigation work.
The reaction
One person, who lives near London Road cemetery, said she heard a loud ‘shot’ noise at around 8.20pm.
She added: “There was a loud car horn and gunshot-like noise in the area. I just remember there being loads of police cars.”
Another local said they heard “all the police sirens” and saw a cordon around the cemetery, but did not see much else happening.
The police cordon that was in place around the cemetery has since been removed.
Some locals said they didn’t find out about the incident until the morning after it had happened.
Robert Rowntree, a warehouse driver for Plumbcity, said: “I first knew about it right before I came into work this morning.
“My colleague said that traffic was awful, so I knew there must have been something big, so I went online and found it all out.”
Alan Snow, branch manager for Wolseley Plum & Parts, added that he heard about it “through word of mouth in the area” as well as online.