Man, 80, to be arraigned in 1991 armored truck guard killing

Ralph DeMasi enters his not guilty plea during his arraignment in the 1991 shooting death of armored truck guard, Edward P. Morlock Sr., Wednesday, Dec. 14, 2016, in Worcester Superior Court in Worcester, Mass. At left is DeMasi's attorney, Michael Hussey. (Christine Hochkeppel/Worcester Telegram & Gazette via AP) (The Associated Press)

Edward P. Morlock Sr.'s widow, Jeannette A. Morlock, reacts as Ralph DeMasi is arraigned in the 1991 shooting death of Morlock, an armored truck guard,, Wednesday, Dec. 14, 2016, at Worcester Superior Court in Worcester, Mass. (Christine Hochkeppel/Worcester Telegram & Gazette via AP) (The Associated Press)

WORCESTER, Mass. – An 80-year-old former associate of ex-Boston crime boss James "Whitey" Bulger is due to be arraigned in the 1991 fatal shooting of an armored truck guard in Massachusetts.

Ralph DeMasi, of Amesbury, will be arraigned Wednesday in Worcester Superior Court on murder and robbery charges in the killing of Edward Morlock. Morlock was shot while carrying bags of money from a Shaw's Supermarket in Worcester (WUS'-tur).

Prosecutors say DeMasi and three others robbed Morlock and escaped in a waiting car. Authorities say the other men have since died.

DeMasi testified during Bulger's 2013 trial, shortly after being released following more than 21 years in prison for a different armored car robbery.

DeMasi could not be reached for comment while in custody. It was unclear if he has a lawyer.