The murders at Koodathayi had some similarities with a serial killing at Pinarayi village in Kannur last year.
The suspect in that case was a woman named Soumya who had administered rat poison to her daughter Aishwarya, her mother V. Kamala and father V.V. Kunhikannan.
The 28-year-old, who was arrested in April 2018, later committed suicide on the compound of the Kannur women’s sub-jail.
In the police investigation, it was found that Soumya had committed the murders within four months to cover up her relationships with a few youths in the nearby villages.
Police misled
The woman had also attempted to mislead the police stating that all the three died after consuming water from a well contaminated with a poisonous substance.
The seven-year-old case was cracked following a complaint by one of her relatives. The body of the child was exhumed for forensic examination, which proved murder.
In both the incidents, the poison was mixed with home-made food. The victims had almost shown similar symptoms though the three in the Pinarayi incident met with a slow death. Both women denied the charges even during long hours of interrogation. However, in the Pinarayi incident, the woman had no support and committed the murders alone.
According to Crime Branch sources, Jolly who was arrested in the Koodathayi incident on Saturday, used to boast of holding high-profile jobs in premier educational institutions. She had claimed to be a permanent employee of the National Institute of Technology-Calicut. Actually, she was running a beauty parlour at Mukkom, the sources said.