There have been few crimes in New Zealand more patently the product of a cold intensity of selfishness than the murder on the Cashmere Hills, Christchurch, in June 1954 of Mrs Honora Mary Parker (otherwise known as Mrs Rieper) by her 16-year-old daughter, Pauline Yvonne Parker, and her schoolfriend, Juliet Marion Hulme, two months younger. The incredible ingredients of the crime were graphically disclosed in the six-day trial of the two girls for murder. Perhaps the most disturbing feature of the murder was the attempt by the two girls to represent their actions as a crusading challenge to the conventional in human behaviour and relationships. Authority and the community were not converted – merely inexpressibly shocked.

Mrs Parker was brutally done to death with a half brick encased in an old stocking which one of the girls had carried around in her shoulder bag for half a day. Moreover, both of the prisoners used the weapon in succession. An “intense devotion” had developed between the pair, and when Hulme's father made preparations to leave for South Africa, Parker refused to accept the inevitable. The two girls resolved to leave the country and later go to South Africa where they would live together. Because they were well aware that Parker's mother would veto such a mad plan, they agreed she must be killed. On what purported to be a farewell outing before the departure of the Hulmes, the two girls battered Mrs Parker to death. The strange relationship existing between them was brought to light by means of grotesque evidence from diaries, attempts at novel writing, and their own statements. Inevitably insanity was pleaded, but strong medical evidence by the defence was rebutted by irresistible testimony by Crown experts, one of the features of the trial being the broadsides of cross-examination of doctors and psychiatrists by both sides. The question was, “Are they mad or bad?” The defence declared they were insane. The Crown replied that they “were not incurably insane, but incurably bad”. The jury did not take long to decide that the prisoners were sane, and unequivocally rejected the invoking by the defence of the M'Naghten Rules (1843) which evolved from a case of delusional insanity, and are still frequently pleaded.

On 25 August 1954 the two girls were sentenced by Mr Justice F. B. Adams to be detained indefinitely. It is probable that a large body of public opinion felt that undue mercy had been shown, but under section 5 of the Capital Punishment Act of 1950, which reintroduced the death penalty, persons under the age of 18 years were excluded from a capital sentence. Parker and Hulme therefore received an indeterminate sentence, and by order of the Executive Council were detained in separate penal institutions. After serving several years they were released and have left the country.