Velten was born in 1916 and lived at Kempen in North Rhine-Westphalia. Over seventeen years she poisoned five people close to her: her father, an aunt, two husbands and a lover. The deaths were spread out and each was recorded as natural at the time, the victims being elderly or ill.
She inherited from several of them and took over property and pensions. The German press called her a black widow, and the length of the series, 1963 to 1980, is what distinguishes it: a poisoning of a family member every few years, each one unremarkable in isolation.
She was arrested in 1982 after a relative pressed for an investigation, and exhumations followed. She was convicted and sentenced to life imprisonment in 1983.
The accessible sourcing is thin: German press summaries and encyclopaedia entries. The individual deaths, the poison used, and the trial evidence are not documented in anything available here, and the place name appears as both Kempten and Kempen; Kempen in North Rhine-Westphalia is the correct one.