The 30-year-old woman, was staying on rent here with her two sons and a daughter from past three months. She had left her husband as he was not working.
The accused youth Ajju used to visit the victim frequently, police said.
Ajju visited her house yesterday where the two had a conversation. He then asked the kids to go out after which he shot the woman and later shot himself dead, they said.
On listening to the gun shots the landlord's family rushed towards her room but informed the police on finding it locked from inside, said police.
The woman's mother also reached the spot but denied any acquaintance with Ajju, said police.
Police had called FSL team on the spot which seized the bullets and a pistol was also recovered from the spot. Further investigations are on, they said.