CHENNAI: The city police on Thursday said a 28-year-old former employee of a software company they had arrested for robbery was a serial rapist who could have sexually assaulted up to 50 women in Chennai.

Investigators stumbled upon the crimes of Madhan Arivalagan , a native of Mathur in Krishnagiri district, after they took him in for questioning in connection with a mugging incident, inspected his cellphone, and were stunned by what they found recorded on the device.

“Arivalagan sexually assaulted women after trapping them alone at home,” an investigating officer told TOI. “He recorded the acts on his cellphone in several cases and used the footage to blackmail and repeatedly rape the women.” “We have received a first formal rape complaint against Arivalagan and expect more to follow,” he said. “Many of the women, of course, may choose to never come forward and charge him.”

Investigators said Arivalagan , a BSc (Maths) graduate from a Krishnagiri college, worked for a software firm in Bengaluru for a couple of years before moving to Chennai in 2015.

“Arivalagan told us during interrogation that he was looking for a job in the city but could not find suitable employment,” the investigating officer said. “He started to rob people on the roads and in their homes, often targeting women who were home alone. He raped one robbery victim and soon gravitated into a sexual predator.”

Police on Thursday detained Arivalagan on a complaint by a software engineer who said a robber had mugged him at knifepoint near his house a few days ago and made away with Rs 8,500 in cash.

A police team identified Arivalagan as a suspect through footage from security cameras in the area and took him into custody from his house.

After checking his cellphone, investigators interrogated Arivalagan about the videos they found. “Arivalagan admitted that he had raped several women at knifepoint in their houses,” the officer said.

