BOSTON -- A woman who was allegedly shot by her husband this weekend has died, the Middlesex County District Attorney said Tuesday.

Authorities said Frederick Leduc, 45, shot his wife before he turned the gun on himself in their Forge Village Road home in Westford at about 7:30 p.m. Saturday.

Karen Leduc, 43, was flown to UMass Memorial Medical Center in Worcester after the attack and died Tuesday, Middlesex County District Attorney Gerry Leone said.

On Monday, Frederick Leduc was charged with armed assault with intent to murder, illegal possession of a firearm, illegal discharge of a firearm and illegal possession of ammunition. After the woman's death, the charges were upgraded to include first-degree murder, Leone said.

Frederick Leduc was arraigned in his hospital bed at Mass General on Tuesday afternoon.

The couple has three sons -- Josh, 24, Jared, 18, and Justyn, 16.

As many as 350 friends, neighbors and the boys' high school classmates packed a Westford church Tuesday night to pray for the family.

Amanda McCarthy, a senior at Westford Academy and classmate of Jared Leduc, said many students and their parents attended a candlelight vigil at St. Catherine of Alexandria Parish.