Investigators believe that a Long Island woman found dead in the back seat of her husband's car last week by a state trooper making a traffic stop on Interstate 95 in Fairfax County was killed near her home in New York, a state police spokeswoman said yesterday.

Although the body of Ruth Baeza, of Franklin Square, N.Y., was discovered in Virginia, the case will be investigated in New York, according to Virginia State Police spokeswoman Lucy Caldwell. Investigators have found evidence that Baeza was shot near a bus stop where the 52-year-old woman took the bus to work each day, Caldwell said.

Baeza's estranged husband, Charles E. Baeza, 51, was charged with murder early Friday after a Virginia state trooper making a routine traffic stop on Interstate 95 found the woman's body in his car, police said.

Trooper F.B. Ingham was writing a traffic ticket in his cruiser when he was startled by a car that nearly smashed into his vehicle as it sped down the highway, police said. Ingham stopped the car, and while he was talking with the driver, he noticed an arm under a blanket.

When the trooper asked Baeza to wake up the passenger, he allegedly replied: "I can't . . . . She's dead," Caldwell said. New York detectives will come to Fairfax County, where Baeza is being held without bond, officials said.