Clementine Barnabet - The Voodoo Murders
The most prolific female serial killer in Louisiana history. Barnabet confessed to 35 murders, but many are questionable. Between 1911 and 1912, many noted a large number of deaths along the Southern Pacific railroad in south Louisiana. Barnabet confessed to these murders, but while she was in custody, similar murders continued in the same area. Barnabet claimed her killings were part of the Church of Sacrifice in Lake Charles. According to her confessions, she claimed he had been granted supernatural powers from a priestess in the church. Barnabet was convicted of the murders in 1912, but was mysteriously released from prison in 1923, and disappeared after her release.
It's possible the whole family was in on the murders as there was many blood covered clothing found in the house. Also while her father sat in jail, the murders continued. Not only that. But when she was arrested the murders continued as well.