Jurors have begun deliberations in the inquest of Mark Duggan, who was shot dead by armed police in August 2011, sparking riots in London.
The coroner said they must be certain the officer who shot him did not honestly believe he needed to use force to defend himself or others and that Mr Duggan was not carrying a gun to give a verdict of unlawful killing.
The jury retired after a three-month hearing in which dozens of witnesses gave often controversial and highly-contested evidence.
Mark Duggan, 29, died in August 2011 after a police firearms team following him forced the minicab in which he was travelling to stop in Tottenham, north London.
Police intelligence suggested he was a gang member involved in gun and drugs crimes and officers believed he had just collected a gun in east London.
A police firearms officer shot him twice as he emerged from the minicab. One bullet went through his arm, the other hit his chest and killed him.
At the centre of the inquest was the issue of a handgun, found, said police, 10 to 20 feet from Mr Duggan's body and on the other side of park railings.
In heated exchanges with the Duggan family lawyer, police denied suggestions they had planted the gun.
The weapon was wrapped in a sock. Neither had any trace of Mr Duggan's DNA or fingerprints.
But his prints were on a shoebox police said had been used to carry the gun inside the minicab.
The firearms officer who shot Mr Duggan was granted anonymity for the inquest and appeared under the code name V53.
Jurors were shown a handwritten note he made within an hour of the shooting, in which he wrote: "I got out of Charlie car. Subject got out of rear near side of taxi holding gun-shaped item in sock in his hand.
"Began to raise it up in my direction. I fired several shots."
But a witness who said he saw the shooting from high up in a block of flats across the road insisted that Mr Duggan looked as though he was surrendering, was only holding a mobile phone and looked "trapped and baffled".
Various members of Mr Duggan's family attended the inquest and his mother Pam said at the start that she hoped "the truth" of her son's death would finally come out.
Community leader Stafford Scott told Sky News: "What's taken place inside the inquest building clearly gives the family heart.
"We have heard the voices of independent witnesses we hadn't heard before. We believe what took place has been properly investigated."
Jurors have been told they can come to one of three conclusions - unlawful killing, lawful killing or an open verdict.
Whatever the jury's decision, there is almost certain to be much criticism of the police watchdog the Independent Police Complaints Commission which investigated the shooting.
It has still to complete its investigation, but in an interim statement in August said it had so far found no evidence of criminality by police officers.
The family has complained it has not been kept fully informed of the investigation's progress and condemned the IPCC for suggesting to the media early on that Mr Duggan, a father-four, had died in "a shoot-out with police".
The IPCC said its investigation has been delayed by police officers' refusal to give face-to-face interviews, instead submitting written statements.
IPCC chairwoman Anne Owers said: "The officers who were present when Mark Duggan was shot all refused to attend to be interviewed though they did agree to answer questions in writing through their solicitors.
"That led to a protracted and profoundly unsatisfactory process that lasted for over six months, during which we wrote questions and they in time provided some answers, which inevitably led to further questions and further partial answers.
"I have described this process as about as effective as putting a message in a bottle and floating it down the Thames."
An IPCC spokeswoman said the coroner had asked it to keep the investigation open in case new evidence emerged during the inquest, which has happened.