Sgt. Marc Simmons, a detective, said 55-year-old Peggy Perez-Olivo died about 3 p.m. at a hospital. He said there are still no arrests.
She was shot in the head, and her 58-year-old husband was shot in the abdomen late Saturday, police said.
The couple — he a recently disbarred criminal defense lawyer, she a teacher's assistant — were driving to their Chappaqua home from Manhattan when they were shot, New Castle Town Police said. According to police, the couple was on a desolate part of Route 100 when a car cut in front of their sport utility vehicle and forced them off the road around 11 p.m.
A man with a gun got out and entered the SUV through a back door, and Carlos Perez-Olivo fought with him, police said. They said they had not been able to identify any suspects or determine a motive.
Carlos Perez-Olivo had practiced law in New York from 1980 until he was disbarred in August, according to state court records. State Supreme Court appellate judges found he "repeatedly refused to return unearned funds or retainers to clients."
He was previously accused of incompetence for failing to recall portions of his closing argument in defense of a waiter convicted of second-degree murder for fatally shooting his wife's lover last year in a Manhattan subway station.
There was no home telephone listing for him or his wife in Chappaqua. No one answered the door Monday at the couple's blue and white Colonial home, one of eight houses on the cul-de-sac. It is three doors away from the home of the former president and Sen. Hillary Rodham Clinton, which has a guardhouse at the foot of its driveway.
Acquaintances said they were mystified by the shooting.
"They're a very nice couple, great folks, sweet people," said their landlord, Gerard Gorman.