Born in Bellaghy, County Londonderry on 8 April 1954, he attended the same school as also future-Provisional IRA members Thomas McElwee, and Francis Hughes.

[2] However, several months later he was part of a successful prison break, and resumed his activities in Northern Ireland.

[2][3] During the mid-1970s, the Royal Ulster Constabulary described Milne as one of its three "most wanted" men in the South Londonderry area, alongside Francis Hughes and Dominic McGlinchey.

In 1977, he was arrested and received a life sentence for the killing of Ulster Defence Regiment (UDR) soldier, James Speer, in Desertmartin on 9 November 1976.

[9] In September 2017 Milne was served a civil writ by the family of James Speer for his alleged involvement in the murder.