Columbia subject headings:
Criminal psychology.
Gun control.
Insanity (Law)
Mass murder--Australia--Melbourne (Vic.)--Case studies.
Mass murder--England--Hungerford (West Berkshire)--Case studies.
Personality disorders.
Psychoses.
Serial murders--Psychological aspects.
Harvard subject headings:
Mass murder--Australia--Melbourne (Vic.)--Case studies.
Mass murder--England--Hungerford--Case studies.
Princeton subject headings: