FAYETTEVILLE, N.C. -

 A federal judge has denied Jeffrey MacDonald's latest bid for a new trial. He's serving three life sentences in the stabbing deaths of his pregnant wife and two young daughters.

The Fayetteville Observer reports Senior U.S. District Court Judge James C. Fox ruled Thursday that MacDonald's lawyers failed to show that their client shouldn't have been found guilty of the murder of his wife and two daughters in 1970.

Fox also said MacDonald's lawyers failed to establish the merits of new evidence presented at a September 2012 hearing.

The 70-year-old former Army captain is serving three life sentences in the stabbing deaths of his pregnant wife, Colette, and 5-year-old Kimberley and 2-year-old Kristen in their Fort Bragg home.

MacDonald was convicted in 1979, but has contended that he and his family were the victims of a home invasion during which he was knocked unconscious and stabbed.