New Delhi, June 6 -- The murder of a 45-year-old assistant professor of a Delhi University college at a high-rise society in Vasundhara Enclave took place within a five-and-a-half-hour window between Wednesday afternoon and evening, the police have ascertained, adding that they have identified 13 potential suspects, besides her estranged husband. Further, only one person was involved in the incident and the suspect was acquainted with the victim, as there was no sign of forced entry, officers aware of the investigation said on Friday. Police said two masked persons, including a woman, were also seen entering the society on Wednesday, and are among the prime suspects. An officer familiar with the probe, requesting anonymity, said the last phone call made by the professor was to her mother, around 12.30pm on Wednesday. Around 6pm, the society handyman arrived at her flat to repair a window, but he found the gate locked from the outside and returned. "Since the flat remained locked from the outside until the locks were broken around 3pm on Thursday, it can be said with certainty that the woman was murdered within a span of five-and-a-half hours on Wednesday," said the officer. The woman's body was found with multiple injuries and cuts to her wrists in her sixth-floor flat when her sister arrived. Investigators said the forensics team found only one set of unidentified fingerprints inside the flat. They said the list of 13 suspects includes a woman, a 10-year-old boy and a man, who were seen entering the A Block of the society together and leaving the premises around 20 minutes later....