These are sanguma men or meri - male or female sorcerers, people who for the most part conceal their skills cunningly.
There are benign sorcerers, who are available to help heal, improve food garden productivity, obtain good exam results or, of course, lure an attractive person to fall in love with you - for a consideration, of course. Some offer a tariff list.
In a remote world lacking scientific explanation, in which life could be brutish and short, it was natural that people sought not only a way to understand how their world worked, but also to find a way to take a measure of control over it.
A six-year-old boy had died after complaining of stomach and chest pains in hospital in Mount Hagen, the largest city in the Highlands.
His relatives, who come from the same area as Lanieta, pointed the blame at her, branding her a sorcerer, invading her home, torturing her with a hot iron bar, stripping her naked, tying her up, setting her alight and throwing her on a rubbish heap.
Passers-by photographed the scene with mobile phones.
Appallingly, such sorcery killings remain comparatively common in PNG. Although the perpetrators often seek admiration for their crimes, few end up in court.
No one has yet been charged in Mount Hagen, even though PNG police commissioner Tom Kulunga described the murder as "shocking and devilish", and "totally unacceptable in the 21st century".
Prime Minister Peter O'Neill has also spoken out forcefully against such "barbaric killings", pointing out that it is usually "women, the old and the weak" who are the targets, the scapegoats for ignorance, fear and revenge.
It took the rape and murder of a 23-year-old Indian student in a New Delhi bus to galvanise parliament and the justice agencies to take crimes against women seriously.
Is it possible that Lanieta's brutal killing could trigger a similar popular campaign in PNG, which could lead to appropriate legislative and educational reform, and to a tough response from the police and courts?