Some 400 people joined a procession last Saturday to commemorate those who have died in police custody.
The march was organised by the United Families and Friends Campaign.
The number of families and campaigns grows each year as the number of deaths increases. It currently stands at 1,578 since 1990, according to charity Inquest.
The demonstration moved from Trafalgar Square to Downing Street, where it heard from some of the justice campaigns.
People criticised the Independent Police Complaints Commission (IPCC) and the procedure for investigating deaths in mental health facilities. Sean Rigg died in police custody in Brixton, south London, in 2008.
His sister Marcia said, “Too many people are dying in mental health settings. NHS providers are investigating themselves. When someone dies, there needs to be an independent investigation.”
Margaret Smith, whose son Jermaine Baker was shot dead by police in Tottenham in 2015, spoke to Socialist Worker.
“The IPCC needs more power to prosecute the police,” she said. “Changes need to be made, maybe their hands are tied.”
Others were scathing about the organisation, however, and called for it to be scrapped.
The crowd heard from Becky Shah from the Hillsborough Justice Campaign about their struggle for justice.
“Never give up fighting,” she said. “Because if we can do it, then so can you.”