A 21-year-old university student who was taken hostage in her apartment and then shot to death during a police standoff with an armed robber on New York's Long Island was killed by a bullet fired from an officer's gun, investigators said on Sunday. Andrea Rebello was shot in the head on Friday by one of eight rounds fired at Dalton Smith, who had the woman in a headlock with a 9mm gun pointed at her head at the time, Nassau County Police Department spokesman James Imperiale said. Smith, 30, was struck by seven bullets and died in the apartment in Uniondale, about a half a mile from Hofstra University. Rebello, who was studying public relations at Hofstra, was taken to a nearby hospital where she later died. Investigators determined that Smith, who had an extensive criminal history and had been released from prison earlier this year, did not fire his gun during the incident, Imperiale said. Nassau County Police Commissioner Thomas Dale traveled to Tarrytown, New York, on