The businessman, Chandrakant Sharma, now claims to have committed 20 other murders nearly 15 years ago in different towns of Maharashtra.
Sharma, a real estate businessman in Bangalore since 1985, is now in police custody after being accused of murdering his landlord SV Raghavan, who was a pensioner.
Police say his wife 43-year-old wife Harsha and 21-year-old son Monto were accomplices in the murder that took place seven days ago.
But it's not just one murder case that has caught the police's attention, it's Sharma's past.
"He has made startling revelations saying he's committed 20 murders in Maharashtra. So a team is being sent to Maharashtra," Gopal Hosur, Joint Commissioner (Crime), says.
Sharma claims he has killed people in Mumbai, Pune, Nasik, Manmad and Aurangabad.
"After you give chloroform there's no struggle. So it's easy to tie and shift the body," he claims.
The police officials are, however, sceptical about many of Sharma's claims.
"It could be that all of it is false. However it is also necessary to verify and find out since these murders are supposed to have taken place 10-15 years back," Hosur adds.
"He says that he paid money to police in some cases and got away. Until we verify all this we have to take his statement with a pinch of salt," Alok Kumar, DCP (South), says.
The police are also planning a lie-detector test on Sharma if needed and if the claims are proved to be correct, he would be the second suspected serial killer to be arrested in Karnataka within a month.
In December last year, the police had arrested 43-year-old Mallika allegedly for killing six women by forcibly feeding them temple offerings laced with cyanide. She used to take their gold after killing them.