When stories about undercover officers spying on political groups first came to light, many thought it was the stuff of film plots.
Today, as a long awaited public inquiry got underway, the search for answers for those who were spied on began.
There are “profound and wide-ranging concerns” over the activities of two undercover police units operating in England and Wales for over 40 years, the inquiry was told.
The secretive units infiltrated political and other activist groups, with some officers forming sexual relationships with the women they were spying on.