Seamus Martin Kearney, 54, of Swatragh, County Derry, was told a life sentence is mandatory, the Belfast Telegraph reported. But the newspaper said under the Good Friday agreement, Kearney is likely to serve only two years.
Belfast Crown Court Judge David McFarland found Kearney was involved in the murder of John Proctor, a part-time member of the Royal Ulster Constabulary, as either the shooter, the get-away driver or as someone at the scene to support the gunman. Proctor was shot soon after a visit to his wife, June, in Mid Ulster Hospital where she had just delivered a son.
Kearney was later linked to the killing by DNA found on a cigarette butt at the scene.
"I am satisfied beyond a reasonable doubt that the defendant had smoked the cigarette and having finished it smoking it, discarded it at, or about the time of the shooting," the judge said.
June Proctor wept after hearing the verdict, repeating "I can't believe it."
Kearney was convicted in 1984 for firing at two Ulster Defense Regiment soldiers. Investigators said the same AR-15 rifle that killed Proctor was used in the later shooting.