Acting on a tip-off, a trap was laid and the accused Selvankumar Nadar was nabbed from Dharavi area and handed over to Pune police.
The accused stabbed to death his mother-in-law Pramani Nadar (52) and injured his brother-in-law Deeprajan Nadar (19) with a sharp object at their residence in Ashok Gaikwad Chawl in Pune yesterday, police said.
Selvankumar, who is also a resident of Pune, had a heated argument with his wife, who went to her mother's house in the same city.
The injured duo was rushed to a nearby hospital, where Pramani was declared dead, police said.
Further probes into the case are on, they added.