Six deaths in one family over 14 years. Police say they have found their killer: The daughter-in-law

Tom and Annamma Thomas were the first members of the family to die.

Koodathayi is an unremarkable landlocked village in the state of coastal Kerala in south India. But in October, police there claimed to have made an "unbelievable" discovery: A woman had killed six relatives over 14 years with cyanide.

Jolly Joseph, a 47-year-old mother of two sons, was arrested in October for the murders of her first husband and five others between 2002 and 2016. Police say she has confessed to the killings.

Joseph appeared Friday before a judge, who ordered that she remain in police custody. Her lawyer says he is preparing to file for bail.

Shocked neighbours described her as "pious," and her sister-in-law said Joseph was "smart and jovial." But in the press, she has come to be known as the "cyanide killer," for the use of the fast-acting poison that police claim was used in the deaths. Two men accused of supplying her with cyanide are also under arrest.

"Initially, it [the case] was quite unbelievable for everyone," said K.G. Simon, the lead police investigator in the case.

The Koodathayi killings are a rare case involving a female serial killer in the country. India's first convicted female serial killer was K.D. Kempamma, who targeted distressed women at temples between 1999 and 2007. She would befriend them, poison them with cyanide and steal their jewelry.

In the recent slayings, the Thomas family, into which Joseph married, thought they were cursed as family members began to die one by one.

The first was Joseph's mother-in-law, Annamma, a retired schoolteacher. In August 2002, she fell unconscious after a meal of mutton soup and died soon after. Six years later, Tom, Joseph's father-in-law, died after eating a plate of tapioca. Neither of the deaths were investigated at the time.

Next to be found dead was Joseph's husband of 14 years, Roy. In 2011, he died after throwing up his meal and losing consciousness. The case was ruled a suicide when cyanide was detected in his body. Three more members of the extended Thomas family died over the next five years.

The case caught Simon's attention after one of the remaining members of the Thomas family requested that police investigate the deaths.

Renji Thomas, Joseph's sister-in-law, said she initially sympathised with Joseph, who was raising two children as a widow. But when Joseph decided to marry Shaju, her deceased husband's cousin, Renji became suspicious.

Shaju's wife and daughter died in similarly mysterious circumstances in the years before the wedding. Alphin, the 2-year-old daughter, died in 2014 during a family function at a church after eating a piece of bread. Her mother, Cily, died two years later after collapsing during a dental appointment. Joseph was present on both occasions, according to police.

Police say they began to suspect Joseph when they discovered she had lied about being a lecturer at a prestigious college. Her cover was elaborate. She had an identity card of the college and would drive to work each morning. Local media reported that she was never employed by the college.

As grisly details of the killings emerge, the case has transfixed the country. Crowds gather at every court appearance to gawk at Joseph, sexist memes have flooded the Internet, and a movie on the murders might be in the works. But even as police claim Joseph has confessed to the crime, prosecuting her in court could prove difficult.

"This is a case which we have to establish with circumstantial evidence," said Simon, the police official in charge of investigation.

No autopsies were conducted in the deaths, except in the case of Joseph's husband, making it difficult to establish the cause of deaths. Confessions made in police custody are not admissible as evidence in court unless made before a magistrate. Witnesses for the deaths from years ago will also be hard to find.

But Renji is confident. "I believe that there is the invisible hand of God in this case," she said. "Otherwise, this wouldn't have surfaced after 18 years."