Justice campaigners and activists attended a conference on police corruption, spying and racism in London last weekend.
Speakers included Stuart Lawrence, brother of Stephen Lawrence, and Janet Alder, sister of Christopher Alder.
The two-day conference examined how undercover police secretly gathered intelligence over two decades on families fighting the police to get justice.
Helen Steel also spoke. She was deceived into having a two-year relationship with undercover officer John Dines.
The event was organised by Centre for Crime and Justice Studies, Imran Khan and Partners solicitors, Monitoring Group and Tottenham Rights, and sponsored by Campaign Opposing Police Surveillance.