This is the 20th and last of the murder cases registered against the criminal, who has killed several women using cyanide after befriending and raping them.
The quantum of punishment is expected to be pronounced on June 24.
The prosecution case was that the 25-year-old victim, who was working as a cook in a ladies hostel in Kasaragod, got acquainted with Mohan in 2009.
He visited her house thrice and promised to marry her.
On July 8, 2009, the woman had left her house, saying she was going to a temple at Sullia.
Mohan took her to Bengaluru and when the family members called him about her, informed them that they had got married and would return home soon.
He had taken the woman to a lodge near the bus stand.
She had a physical relationship with him and before leaving the next day, was asked to leave her jewellery in the room.
They went to the bus stand where he gave her a cyanide laced tablet, making her believe that it is a contraceptive pill and left the place, the prosecution said.
The woman consumed the tablet and collapsed near the toilet of the bus stand.
She was rushed to a hospital by a constable, but was declared dead on arrival.
A case of unnatural death was then registered.
After Mohan was arrested in October 2009, the victim’s sister, seeing his pictures, identified him and filed a complaint, following which the criminal investigation department took up the probe.
Public prosecutor Judith O M Crasta had argued the case earlier, which was taken over later by Jayaram Shetty.