Of the six cases featured in the latest Murder by the Sea series, Louisa May Merrifield’s is the one I would most like to research further.

The Blackpool Poisoner was the final episode on CBS Reality’s British series last week, and it is fascinating.

In 1953 Louisa went to work as a housekeeper for a rather cranky old gal called Sarah Ricketts, aged 79. As I point out during the programme, Louisa was something of a dodgy character, having had 20-odd jobs in three years prior to this.

Murder at the bungalow

Louisa and her third husband, Alfred (who was 24 years her senior at 71) moved into Mrs Ricketts two-bed bungalow at 339 Devonshire Road, Blackpool.

The housekeeper got her employer to change her will, leaving her £3,000 bungalow to Louisa and her husband. Soon after Louisa put rat poison in the old lady’s favourite treat – a jar full of jam.

As Murder by the Sea makes, Louisa was greedy and boastful. She made several blunders and was soon arrested.