The inquiry was triggered by a 1991 World in Action documentary which aired allegations of systematic abuse. The core of the investigation was the death of Sean Walton, a young patient who had been found dead in a seclusion room in 1988 after allegedly being punched by a nurse. The initial internal investigation had cleared the staff, but Blom-Cooper found that the hospital had "closed ranks" to protect its own.

The report exposed a chilling "penal" culture. Patients were often treated as prisoners rather than people with mental health conditions. Key findings included:

• The "Big Three": A group of powerful nursing officers (associated with the Prison Officers Association) who effectively dictated hospital policy through fear and intimidation.

• Psychological Warfare: Staff used "degrading and dehumanising" punishments. In one instance, a pig's head was used to frighten a patient; in others, patients were mocked for their disabilities or ethnic backgrounds.

• Institutional Racism: The report found "appalling" evidence of racial prejudice. Black patients were subjected to harsher restraint and more frequent seclusion than white patients.

• The "Seclusion" Culture: Seclusion (solitary confinement) was used as a routine punishment for minor infractions, such as "answering back," rather than as a last-resort clinical intervention.

Blom-Cooper famously concluded that Ashworth was a "professional island" that had drifted away from the rest of the NHS. He argued that the hospital was "not a therapeutic community" and that the management was "frightened of its own staff."