Creeslough man John Downey has been refused bail in the High Court in Belfast.
The 67-year-old is charged murdering two British soldiers in 1972 must remain in custody.
Downey was refused bail amid fears he could flee before any trial for the car bomb attack which killed Ulster Defence Regiment members Alfred Johnston and James Eames in Enniskillen, Co Fermanagh.
Mr Justice Horner cited the “real and substantial risk” he could attempt to abscond.
The judge said: “Given the applicant’s age, if convicted he may well remain in custody until his death.
“He does not enjoy good health, and any period of custody will be onerous.”
Downey is facing prosecution after losing a battle against being extradited from the Republic of Ireland.
He was detained in October 2018 under a European Arrest Warrant, exhausting all appeals before handing himself in to the authorities earlier this month.
Lance Corporal Johnston and Private Eames died in an explosion on the Irvinestown Road in August 1972.
They were carrying out checks on a car when a command wire initiated device was detonated, killing them instantly.
The bomb went off as a truck carrying 13 off-duty soldiers approached, blowing it onto its side and injuring some of the troops inside.