A fortnight after senior crime journalist Jyotirmoy Dey was shot dead, Mumbai police on Monday cracked the case claiming that underworld don Chhota Rajan was behind the murder, even as they remained tight-lipped about the motive. "The murder was planned by Rohit Thangappan alias Satish Kalya at the behest of Chhota Rajan. Kalya is a known shooter of Rajan gang and has worked for him earlier too," Joint Commissioner of Police (Crime) Himanshu Roy told reporters. "While three persons were arrested from Mumbai, three were arrested from Rameshwaram in Tamil Nadu and one from Solapur, he said. According to police, Kalya had received a call from Chhota Rajan around 20 days before June 11, the day when Dey was shot dead. Rajan told Kalya he needs him to do a job and that money and weapons would be provided. Kalya then collected Rs two lakh from Chembur and the murder weapon along with 25 rounds of cartridges from Nainital," Roy said.