Jolly Shaju began with her mother-in-law in 2002. She went on to poison her husband and four other members of his family over the next 14 years, by her own admission, and is now suspected of being behind the deaths of at least two others and the attempted murders of several more.
Revelations in the case have shocked and transfixed the south Indian state of Kerala since Ms Shaju's arrest last Friday.
The murders appear to be bound up in the life of lies spun by the 47-year-old resident of Koodathai, in northern Kerala. She claimed to have been a lecturer at Kozhikode’s National Institute of Technology, and to own a share of a beauty parlour near the institute. She has admitted to the killings, police said on Monday, as well as to the fabrications.
Ms Shaju’s mother-in-law, Annamma Thomas, died after eating cyanide-laced mutton soup. The father-in-law, Tom, became the next victim in 2008, and her husband Roy three years later. Traces of cyanide were found in Roy’s body after one of his uncles demanded a post mortem, but the death was deemed a suicide.
The uncle himself was killed in 2014, after drinking cyanide-laced coffee.
In 2017, Ms Shaju married her late husband’s cousin, Scaria Shaju, after killing his wife Cily a year earlier and their two-year-old daughter, Alphine, in 2014.
When Cily was found unconscious and breathing with difficulty soon after Alphine's death, her family took her to hospital, thinking that she was reacting to something she ate. Her stomach was pumped, and she recovered. She was taken back to the same hospital in 2016 with the same symptoms, but did not survive.
Police finally acted after Roy's brother Rojo, who lives in the United States, filed a complaint last month. The bodies of all six victims have been exhumed for forensic analysis. Along with Ms Shaju, police have arrested a friend who allegedly supplied her with cyanide and another man who is believed to have procured it for them.
K G Simon, a local police official, said Ms Shaju was driven by a number of motives. She killed her mother-in-law because Annamma Thomas controlled decisions of wealth and property in the family. She killed her husband after their marital relationship deteriorated. “Jolly had said many times in the past that she wished she had a husband like Shaju,” Mr Simon said.
Mr Shaju told reporters on Tuesday that he had harboured “some doubts” about his wife. “She was the one who initiated the idea of our marriage,” he said, according to a report in The News Minute website. Mr Shaju has also told the media that his wife owned a number of mobile phones, and that she was always speaking to people on one or the other of them.
He insisted that he had nothing to do with any of the killings, although he refused post mortems on his wife and child when they died.
Members of the Thomas family have now raised suspicions about the deaths of two of Tom Thomas’ nephews. Vincent, whose body was found on the day that Annamma Thomas was buried, was thought to have hanged himself. The other nephew, Suneesh, died in an apparent motorcycle accident in 2008.
Mr Simon said there had been other “incidents in the family” that the police were investigating. These were instances in which children suffered seizures, frothed at the mouth, and had trouble breathing, as if they were poisoned. None of them died, he said, but “the family has doubts”.