Police investigating the murder of the 27-year-old researcher,whose body was found in the laboratory of Dayal Bagh Educational Institute on March 15,on Sunday released sketches of three suspects. The sketches were prepared on the basis of information given by two students,the police said. Sources said,the students told police that the three men were seen moving around the laboratory in a suspicious manner on the day of the murder. SSP Agra Subhash Chandra Dubey said that while two of the suspects appeared to be young,the third was around 33 years old. One of them was said to be wearing spectacles,while another reportedly had grey hair.