Doctor Mort Gustafson is a forensic pathologist who works in the Chicago Police Department's 27th District morgue. He was imprisoned at Auschwitz concentration camp as a boy. He is comfortable and playful with his dead patients and loves to sing to them. A great lover of the opera, Dr Gustafson occasionally invites Constable Fraser to accompany him to concerts. Detective Kowalski's stomach turns every time he has to go down to the morgue and tends to look away. Robert Fraser's ghost occasionally pays a visit to Dr Gustafson who is unaware of his presence.
Dr Gustafson was portrayed by the late Czech actor Jan Rubeš.