Jaipur: In a chilling seven-year-old case from Jhalawar, Rajasthan, the Special SC-ST Court on Wednesday convicted four individuals for the murder of Intelligence Bureau (IB) officer Chetan Prakash Galana. The officer was killed in a premeditated plan involving an overdose of anaesthesia. Two prime accused, constable Praveen Rathod and his associate Shahrukh, have been sentenced.