The baby died at the Westchester Medical Center early Wednesday morning from his injuries, said Det. Sgt. Brian Corbett.
The baby, who was being pushed in a stroller, was hit June 26 along with his mother, 38, and two sisters, ages 13 and 9, by Albert Gomez, 62, of Spring Valley.
Police said Gomez plowed into the family while he was passing on the shoulder of the roadway in pursuit of a taxi driver from Motty's Car Service whom he said had cut him off in traffic.
Witnesses said Gomez threw a cup out the window and began weaving in and out of traffic chasing the taxi right before he hit the family.
Gomez was arrested and charged with two felony counts of second-degree assault; two counts of third-degree assault, four counts of second-degree reckless endangerment and one of reckless driving, police said. He is being held at the Rockland County Jail on $150,000 bail.
The Rockland County District Attorney's Office will determine if the charges against Gomez will be upgraded now that the infant has died.
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