Police arrested a 21-year-old visual communication student for the April 18 murder of a transgender in Perungalathur near Tambaram on Wednesday.
Investigators zeroed in on Manivakkam resident S Satish, when he switched on the mobile phone he had snatched from Pooja after murdering her. A court later sent him to Puzhal central jail.
During interrogation, Satish, a final year student of a college in Meenambakkam, said he attacked the 28-year-old transgender with a knife on the railway tracks near Perungalathur junction and left her to die.
He claimed he was returning from a short film shoot near Anna Nagar when Pooja stopped him, began an argument with him and even tried to snatch his bag, Peerkankaranai inspector R Srikanth said to Times of India.
She continued to abuse him and tried to extort money from him when he pulled out a button knife that he always carried as a precaution and stabbed her repeatedly, Satish said in his confession.
He then snatched her phone, turned it off and fled home. He went into hiding for a few days. After his return, Satish continued going to college and went on with his regular routine as if nothing had happened, a police officer said.