Comment from Marjorie Wallace, chief executive of the mental health charity SANE, on BBC2's screening of Why Did You Kill My Dad?
"The way Julian Hendy documents the death of his father is both shocking and familiar. His brave film reveals the reality of under-treated mental illness without condemning those who suffer, while raising urgent questions about the way we treat such homicides.
"Random killings by a person with mental illness are relatively rare approximately ten a year but nonetheless can be devastating for the victims' families, the perpetrators and their families.
"There have been more than 600 inquiries into homicides by people with mental illness, and SANE's own analysis reveals that one in three could have been prevented had mental health services responded to warning signs, shared information, and taken into account previous history and the concerns of friends and relatives.
"Unfortunately, to reduce stigma there is a trend to underplay the scale of these tragedies, but this does a disservice to everyone involved and prevents lessons from being learned."