Ramavat, arrested from Jamnagar yesterday, had earned the sobriquet "stone-killer" as he killed the victims by hitting them on head with a stone.
Sagar Mewada, his first victim, was killed on April 20, followed by Pravin Barad (May 23) and Vallabh Rangani (June 2).
"We have found trace of semen on the bodies of two victims, which showed he had sexual intercourse with them before killing them," city police commissioner Anupamsinh Gehlot said.
"Some 12 years ago, an unidentified person sexually abused Ramavat and offered him money for it. Following this, he started indulging in homosexual activity, primarily for earning money," Gehlot said at a press conference here.
Also Read
"When he could not get enough money any longer this way, he started looting his targets and killed them.
"He informed the family members of the victim (using the victim's mobile phone) about the murder," the commissioner said, adding that (information) helped police in tracing his movements.
Ramavat did not suffer from any mental disorder and was "mentally fit," Gehlot said.
Police tracked his movement after each killing from the mobile phone record, which led them to Rajkot railway station. According to police, he lived in Jamnagar, but came to Rajkot for committing the crime and went back.
Further probe is on, Gehlot said.