The special team probing the case traced the trio with the help of advanced technologies, as the CCTV footage was not clear enough to identify the suspects.

Ranjith (18) was stabbed on his neck late on January 22 near Loyola College in Nungambakkam while he was returning home after attending a birthday party. 

The accused, Karthikyen (21) of Thiru Nagar in Vadapalani, Naveenkumar (22) of Saligramam and Sivaganesh (21) of Alapakkam, were under the influence of drugs when they killed Ranjith when he resisted their attempt to snatch his mobile phone, said police. The trio bought ganja in Pulianthope, the investigation officer added. 

Despite the setback due to unclear CCTV footage, the team managed to establish the registration number of the bike on which the three were travelling, and traced them to Vadapalani with the help of footages along the route. 

“They had switched off their phones while committing the crime, believing that this would help them evade detection. But they have been traced and arrested, and the police have recovered the knife that was used to stab Ranjith, clothes they were wearing on that day, and ganja,” said an officer. 

The three were involved in mobile phone snatching in the past, apparently to buy ganja, but this is the first time they were caught, added police.