The killing of a gold merchant at Bestavaripeta in Prakasam district on Thursday night seemed to be the handiwork of a professional criminal gang, Superintendent of Police K.Raghuram Reddy said on Friday.

The SP, who visited the scene of offence to speed up probe into the murder for gain, told reporters that investigation revealed that a six-member gang that had come by three motorcycles had opened fire with a semi-automatic country-made pistol with 7.65 mm calibre at a close range and decamped with gold jewellery worth Rs 20 lakhs and Rs 5 lakh.

''We have recovered an empty cartridge from the spot and are probing from all angles to achieve a breakthrough in the case'', he said.

The offenders before striking on Thursday had seemed to have kept a close watch on the movements of the trader, Narayana who used to take home the displayed jewellery and cash after closing his shop at night, the SP said.

''Seven teams have been constituted. Our counterparts in Nellore, Kadapa and Kurnool were alerted,'' Dr Reddy said.

Probe revealed that one of the assailants had abandoned a motorcycle and had boarded a Chirala-bound RTC bus before getting down at Turimella near Cumbum.

The incident was part of a series of recent robberies in gold shops in different parts of the state including in the districts of Krishna, Nellore and Visakhapatnam where the offenders had assaulted gold traders with or without firearms and made away with the valuables, he added.