Ngunhnemi, who was found dead by her son, Tlanmawia, on March 16, was buried in the village cemetery on the same day.
"Tlanmawia reached home late on the night of March 15 and went to bed thinking that his mother was fast asleep," said C Zoenga, president of the Muallianpui village branch of Young Mizo Association (YMA).
When he found his mother dead the following morning, he informed neighbours and relatives.
After the woman's funeral, relatives found over Rs 20,000 missing from the house. Earlier, some YMA leaders, who attended the funeral, had reportedly found the woman's neck broken.
Following this, the relatives filed an FIR at South Vanlaiphai police station on March 19. A day later, Lalrindika (29) was arrested. Police said Lalrindika confessed to the crime. He has been remanded in judicial custody.
Lalrindika reportedly told police he was stealing money from Ngunhnemi's room when the elderly woman caught himt. He flung her off and snapped her neck.
The YMA leaders said Lalrindika had been arrested earlier for allegedly murdering a young boy in a forest near Lungtian village.
"He was released for want of evidence and has committed many a petty crime since then," the leaders said. Villagers on Monday took out a procession condemning the murder of the woman.