More recently, McDonald has written on loyalist paramilitary groups and has co-authored books on the Ulster Volunteer Force and Ulster Defence Association with Jim Cusack. He also wrote a biography of Ulster Unionist leader David Trimble. He was, for a period, a security correspondent for the BBC in Belfast and has since criticised the BBC for burying stories which raised doubts about the intentions of the Provisional Republicans in the peace process. In this regard, he specifically cited the killing of Garda Jerry McCabe. During the 1990s he was a staff reporter at Belfast newspaper The Irish News where he edited the youth pages.