Whether someone uses a knife, suffocation, kicking and hitting, or poisoning in committing a homicide is associated partly with their history of mental illness and diagnosis, a study has found.

The authors, from Manchester University, conclude: “Strategies to reduce homicide in the mentally disordered population will therefore need to reflect these differences.”

Part of the national confidential inquiry into suicide and homicide by people with mental illness, the study looked at methods of homicide and psychiatric diagnoses in all people convicted of murder, manslaughter, and infanticide in …