Original sentence: Gray attended Port Chalmers Primary School, and later Otago Boys' High School from 1971 to 1973, where he was a mid-stream student.He had two  siblings, sister Joan and brother Barry.He was born on 20 November 1956 to Mary Elizabeth and David Francis Gray.His father worked in a manufacturing company and his mother was a machinist.His sister said her death deeply affected him, and this prompted him to move from Port Chalmers to the family holiday home at Aramoana.The perpetrator of the massacre was 33-year-old David Malcolm Gray, a resident of Aramoana
Edited sentence: Gray attended Port Chalmers Primary School, and later enrolled at the Otago Boys' High School from 1971 to 1973, where he was a mid-stream student.Gray was born in Dunedin, New Zealand, and was raised in Port Chalmers.He had two siblings, sister Joan and brother Barry.His father, David Francis, worked in a manufacturing company and his mother, Mary Elizabeth, was a machinist.His sister said her death deeply affected him, and this prompted him to move from Port Chalmers to the Gray family holiday home in Aramoana.The perpetrator of the massacre was 33-year-old David Malcolm Gray (November 20, 1956 – November 14, 1990), was an unemployed resident of Aramoana