Janet Alder told a vigil in Hull last Saturday, “I am not working alone and this crowd of people is proof of that.”
Janet is the sister of Christopher Alder, who died in the custody of Hull police 16 years ago.
She was joined outside Hull Combined Court Centre by around 50 supporters.
These included Carole Duggan, the aunt of Mark Duggan, and Wesley Ahmed, the cousin of Anthony Grainger who was shot and killed by Greater Manchester Police in 2012.
Janet said, “There have been thousands of deaths in police custody since 1969 and no one has ever been held accountable. I will not stop until justice is done.”
Supporters marched through Hull to the Unison office where they held a meeting on fighting injustice.
Last week a newspaper alleged that the cops accused of killing Christopher were cleared after incriminating CCTV footage was not submitted to their trial.