On Tuesday, over 100 people gathered outside Tottenham police station in north London to remember Mark Duggan, who was killed by police officers in 2011.
Duggan, a 29-year-old father from Tottenham, was shot dead by a police officer on 4 August 2011. According to official reports, Duggan was shot twice after he was forced out of a minicab by 11 specialist firearms officers, who claimed they were searching for a handgun.
Police did not find a firearm on Duggan after he was killed, while a gun was discovered 14 feet away from the scene of the shooting.
Duggan's death sparked a number of large-scale riots across London and other major cities in the UK, resulting in five deaths and hundreds of injuries.
Last year, the UK's policing watchdog, the Independent Police Complaints Commission (IPCC) cleared the officers involved in Duggan's death of any wrongdoing.
Since the killing, Duggan's family and a number of activist groups across the UK have criticised the police and government authorities for their failure to bring police officers to justice.
As a result, Duggan's mother, Pamela, has called for an urgent inquiry by the home secretary into the events that led up to her son's killing.
In a petition posted on the campaign's change.org page, Pamela Duggan says:
It has come to light that the man who passed a gun to Mark before he was killed was not arrested weeks earlier, despite evidence he was known to officers and had used the same weapon in another attack. If Trident acted more responsibly, Mark may not have been killed and Londoners would not have witnessed violent public disorder on its streets which traumatised our city.
To know that my son's tragic death could have been avoided is devastating. I need Operation Trident and the Met police to take responsibility for their actions. That's why I'm calling on the home secretary, Theresa May, to launch a full, judge-led, public inquiry into the practices of Operation Trident; the alarming use of lethal force and rise in deaths in police custody, the deployment and protection of informants and the supervision of police operations that affect black, Asian and minority communities.
Stafford Scott, an advocacy officer at the Monitoring Group, who has been a long-time campaigner for the Duggan family, announced the launch of a "national injustice day".
Scott told supporters at Tuesday's rally that the decision made by the IPCC "was perverse" and that it had ignored witnesses who said Duggan "could not possibly have possessed or thrown away a gun".
"Four years on and here we are... We [must] keep on fighting, and keep on inquiring. No matter how long it takes, we will come back here," he said.
"We want a judge-led inquiry into the circumstances surrounding Mark's death... We don't want to be known for violence or rioting, but rather to be the community who stood up."
He added: "We want to make sure the young ones here don't become the next victims."
Scott also said that the Duggans, as well as other families campaigning for justice against police violence, would hold another demonstration later in the year.
"We are confident that we will prove the police officers were directly involved in corrupt practices," he said.
Other speakers included a number of local community activists, including the rapper Akala.
The rally was attended by a number of social justice campaigners and relatives of people who died following contact with the police, including the families of Roger Sylvester, Cynthia Jarrett and Joy Gardner.
Jarrett's sister Patricia also spoke.
"Police have been killing our loved ones for decades," she said.
"Half of police custody deaths have been of black men with mental health issues... They come out of the system madder, or dead."
Becky Shah, a representative for the Hillsborough Justice Campaign, who lost her mother during the Hillsborough disaster in 1989, when 96 people were killed in a crush of football fans that many blame on lax policing, told BuzzFeed News that the event was "for all families, friends, and communities affected by state injustice.
"It's brought together all kinds of people who have been affected by injustice at the hand of the state."
Many people at the event said they had also come to protest against police violence toward black people and other ethnic minorities.
Josh, 24, who declined to provide his last name, told BuzzFeed News: "I've come here to pay my respects, but also to protest against institutional racism within the police force.
"Since Mark's death, policing has pretty much stayed exactly the same – just last week, I was stopped and strip-searched by the police for no reason. They deliberately target black and Asian people."
Adam, a 22-year-old student from London who also did not provide a last name, said he came to "support all the victims of police brutality".
"This is close to my heart, because I was in London when the riots kicked off, he said. "Many of my friends got caught up in it, and afterwards were victims of stop-and-search by the police, even when they've done nothing wrong."