Amit Agarwal’s in-laws’ house in Phoolbagan area on Tuesday. (Express Photo by Partha Paul)

After a 42-year-old chartered accountant allegedly killed his estranged wife in Bengaluru, shot dead his mother-in-law and took his own life in Kolkata’s Phoolbagan area, the police on Tuesday said the “planned” murders and suicide were a fallout of a bitter custody battle for his son.

According to police, a 67-page typed suicide note was recovered from the Phoolbagan apartment where following an altercation, Amit Agarwal had allegedly killed his mother-in-law, Lalita Dhandhania, aged around 60 years. He then shot himself dead.

Police said the man had wanted the custody of his son, which was contested by his wife, Shilpi. In his suicide note, Agarwal claimed that he had killed Shilpi in Bengaluru before flying down to Kolkata on Monday.

It was also learnt that the man had also brought his son from Bengaluru to Kolkata. After landing at the city airport, he had asked one of his friends to take his son to his brother. From the airport, Agarwal went his in-laws’ house in the Phoolbagan area.

The police said the woman’s body was found in her Whitefield flat in the Karnataka capital.

“Bengaluru Police informed us that Shilpi’s body was found in a decomposed state. As per their report, she might have been killed at least 48 hours before her body was found,” a senior police officer said.

Police said the Agarwal couple, both chartered accountants, had separated nearly two years ago and was fighting a legal battle for divorce. Shilpi had been staying in Bengaluru with their son, while Amit lived at Uttarpara in North 24 Parganas.

His father-in-law, who managed to escape, had informed police who found Agarwal lying in a pool of blood and the firearm on the floor.