Oklahoma City police are investigating a homicide after an assault victim died at a hospital on Wednesday.According to police, a medical call was made just after 3:30 p.m. to a parking lot near Southwest 59th Street and Pennsylvania Avenue. At the time of the call, police said they were not needed and did not arrive at the scene due to it being a medical call for service. The victim, 39-year-old Calvin Harjo, was taken to a local hospital. Police said they later learned the victim was listed in critical condition and was not expected to survive. Officers arrived at the original scene to begin an investigation. They learned the victim was involved in an altercation with another unknown person and an assault occurred. The victim was pronounced dead on Thursday morning.Police said currently this is still an open investigation. Anyone with any information is urged to contact the Homicide Tip Line 405-297-1200.