While others celebrated Christmas 2011 with their nearest and dearest, the atmosphere was less than festive in the Springfield, Missouri, home of church organist Diane Staudte, 51, who had other things on her mind. The time had come, she decided, to downsize her dysfunctional family.

She hated her 61-year-old husband Mark, whose strong political opinions prompted him to write regularly to the press. He’d never had a steady job, and he’d recently given up any attempt to work, spending his time instead playing for a band – Messing with Destiny, best known for their track “Female Judas.”

Diane’s 26-year-old, semi-autistic son Shaun was another problem. She considered him “worse than a pest,” and her opinion of her daughter Sarah, 24, was little better – she wouldn’t seek employment and was a burden to her, Diane complained. The only two members of the family who were ever of any use to her were her daughter Rachel, 22, and Rachel’s 11-year-old sister.

Having decided that the troublesome trio had to go, Diane and Rachel researched poisons together on the internet.

Antifreeze, they learned, had a very sweet taste, could easily be mixed in a drink, and could go undetected by both the consumer and the authorities…