Ian Tomlinson died after he was allegedly pushed to the ground by a police officer when he was caught up in G20 clashes.
His family and campaigners gathered for a vigil to mark the first anniversary since his death.
An atmosphere of sadness and simmering frustration was palpable at a vigil held at the spot where Ian Tomlinson died last year.
His family say they want justice.
About 50 human rights campaigners joined his relatives at Cornhill, near the Bank of England in the City of London, for the event.
Trembling with emotion, his wife Julia Tomlinson, and son, Paul King, laid flowers and bowed their heads tearfully during a minute-long silence to remember a man whose death came to symbolise the mass protests that he had not even been part of.
Police closed the road for a short period, which meant the silence brought momentary calm to a usually bustling and vibrant street in the heart of London's financial district.
After the vigil, Mr King said: "It's been a year and we are still in the same place. There's still nothing been done. We just want justice, really. We just want to get our life back. It's been a long wait."
Mr Tomlinson's relatives and campaigners were united in their calls for the Crown Prosecution Service (CPS) to decide whether to charge the police officer who allegedly assaulted the 47-year-old newspaper seller with manslaughter.
"It's really frustrating. It's not as if we can pick up the phone to the CPS and say 'What's happening?'"
He said his family "just want justice", adding that he hoped "we aren't here this time next year without a verdict".
Mr Tomlinson died after he was allegedly struck with a baton and pushed to the ground by a police officer during clashes on 1 April 2009 - a moment which was caught on camera by a visitor to London.
The newspaper seller was not a protester. He had been walking home past the demonstration.
Post-mortem examinations later found his death may have been due to a heart attack or abdominal bleeding.
In August, the Independent Police Complaints Commission (IPCC) passed a file on the death to prosecutors.
In a statement Keir Starmer, who heads the CPS, said the CPS and IPCC were working "as quickly as possible" on the "difficult and complex case" but were waiting for clarification on some expert medical evidence.
He said: "I readily accept the responsibility of the CPS to fulfil its duty regarding the investigation into the death of Ian Tomlinson.
"That investigation must be thorough, effective and impartial. And, I am afraid, in this particular case that means that it is taking longer than originally expected."
Mr Starmer also said he acknowledged the family's "frustration and anxiety".
The Met Police said it would not be appropriate for the force to comment while the matter was in the hands of the CPS.
The family have previously called for a full investigation into his death and, in December, lodged a fresh complaint with the IPCC.
At the spot where Mr Tomlinson passed away, one campaigner held a placard which read "one year on and still no justice".
It seemed to sum up the prevailing mood.
The Reverend Phil Summers, from the Methodist Church in Tower Hamlets, whose short prayer stressed that "a year is a long time", said the last 12 months had been "a year of waiting, a year of missing, a year of longing".
The notion of waiting, along with a desire to keep Mr Tomlinson's memory alive, was a recurring theme among those who attended the vigil.
"I wanted to show the Tomlinson family that people care what happens and haven't forgotten," said 15-year-old Aimee, from Hackney, east London.
A member of the Whitechapel Anarchist Group who goes by the pseudonym Eric Blair said his involvement in the G20 protests meant that he felt "partly responsible" for Mr Tomlinson's death.
Then, directing his ire at the authorities, he said: "It's a disgrace that it's been a year and absolutely nothing has been done," adding that he was "not surprised" that no action had been taken because the police "bully us every single day".
He made reference to another controversial police-related flashpoint of last year's protests, in which a Metropolitan Police officer was accused of striking a woman with a metal baton, as an example of what he argued was state-sanctioned brutality.
On Wednesday that officer, Sgt Delroy Smellie, was cleared of wrongdoing after denying common assault on a woman during the protest in Exchange Square, London.
The officer told City of Westminster Magistrates' Court he feared objects in her hand were weapons and the judge said no evidence had been provided to show use of the baton was not measured or correct.
Other campaigners stressed the importance of accountability.
"There is a dangerous trend that the actions of the police go unchallenged," said Patrick Ward of the United Campaign Against Police Violence.
"We've had a year and we still haven't had justice for Ian Tomlinson. It shows that there seems to be one law for police officers and one law for everybody else."
He called for "justice, not just for Ian but for other people who have died at the hands of the police over the years".
Samantha Rigg-David, whose brother Sean Rigg died in police custody in Brixton, south London, in August 2008, backed this call.
"Everybody saw what happened on camera," said Ms Rigg-David, who asked why it had taken "so long" to bring about a legal case against the officer involved.
She said there was a need to bring about a prosecution for one reason in particular: "It will show police officers that they aren't above the law."