A sound assessment needs a complete chronology. It should include the triggering situation, the people involved, any order, the response, the alleged danger, the warning and the start of the force. The individual acts, duration, end and result are equally important.
Secure written orders, incident records, notices, medical documents and personal notes with dates. Where injuries are alleged, medical findings, photographs and treatment details should be organised as close to the event as possible. The records should distinguish personal observations from later assessments.
A four-column table can help: time, observed event, response by prison staff and supporting evidence. This makes it clear where the statutory reason, warning or limitation to the necessary extent remains unresolved.