Columbia subject headings:
Crime--California--Biography.
Criminal psychology--Case studies.
Mullen, Herbert William.
Murder--California--Case studies.
Harvard subject headings:
Criminal psychology--Case studies.
Criminals--California--Biography.
Mass murder--California--Case studies.
Mass murderers--California--Biography.
Mullen, Herbert William.
Mullin, Herbert William.
Murder--California--Case studies
Princeton subject headings:
Case studies.
Criminal psychology--Case studies.
Mullen, Herbert William.
Murder--California--Case studies.
Murderers--California--Biography.