Jinto was a native of nearby Kodencherry.
Police said Sunil (42) stabbed his wife Bindu and Jinto with whom she was reportedly having an illegal affair, in a fit of rage last evening after an argument.
Both of them were admitted to the KMCH. The woman is still undergoing treatment.
Bindu has been working at the firm owned by the deceased.
They were in court as part of an ongoing litigation between the couple over possession of their two sons.