The Hillsborough investigations gathered and reviewed a vast quantity of evidence. The IOPC and Operation Resolve re-examined the documents disclosed to the HIP, having brought them back together in a single location from archives around the UK. The investigation teams also obtained, and restored, the HOLMES databases (specialist IT systems used to support large police investigations) used by the previous investigations into the disaster. In addition, the teams reviewed 2,700 individual pieces of AV material from broadcasters, CCTV and audio recording systems, as well as approximately 23,000 still images.
The material disclosed to the HIP included minutes and notes from a large number of meetings involving police officers and other parties. These included meetings after the disaster between SYP officers and its appointed legal team. While these would have been conducted under legal professional privilege, because the meeting minutes were disclosed to the HIP, the documents entered the public domain and could be used as evidence.
