NY mayor Bill de Blasio said the suspect is a former US Navy serviceman and a US citizen and there is no indication it is connected to terrorism.
"She was a terrific young lady. and we will really miss her", Eric Alburtus, principal at Portage Central High School, said.
A auto plowed through pedestrians in Times Square in New York City Thursday around lunch time.
He reportedly told officers he had smoked synthetic marijuana before charging into the bustling tourist destination, where 18-year-old Alyssa Elsman had been visiting with her mother and 13-year-old sister.
Two law enforcement officials say a driver accused of running down pedestrians in Times Square told officers he was hearing voices and expected to die.
NYPD Commissioner James O'Neill said the suspect was 26-year-old Richard Rojas, a resident of the Bronx and a Navy veteran.
Initial reports of the incident brought to mind vehicle attacks on pedestrians in recent months in Britain, France, Germany, Israel and Sweden.
Speaking to reporters Thursday afternoon, Mayor Bill de Blasio said the crash was not an act of terror.
Friends said the 26-year-old was in good spirits the night before the attack, but had been changed forever by his time served in the military and would often drink to numb the pain. He was in custody, and it wasn't clear if he had an attorney yet who could comment on his behalf. Faisal Shahzad, a naturalised American and Taliban-trained militant, later pleaded guilty and was sentenced to life imprisonment.
Police sources said the suspect, who has two previous arrests for drunk driving, was being tested for alcohol.More news: US, Turkey Spar Over Erdogan Visit Violence
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Police say they do not now believe the crash was in any way linked to terrorism.
Rojas enlisted in the Navy in 2011 and was an electrician's mate fireman apprentice. Details were not immediately available. "I mean she just got to NY, that's her happy place".
White House spokesman Sean Spicer said President Trump was made aware of the incident. The vehicle, a maroon Honda Accord, had traveled along the sidewalk for more than three blocks.
One picture showed what appeared to be the dead woman in the middle of a pedestrianised area with a broken off wing mirror lying next to her. In 2010, a auto bomb was disarmed before it could detonate in Times Square.
Victims had no time to react and scramble for safety in crowded Times Square, said Alpha Balde, a sightseeing-ticket seller.
One surveillance video showed the maroon vehicle jump the curb and slam into a group of people, sending bodies tumbling over the hood of the speeding Honda Accord.
"On behalf of the Irish Government, I wish to express our condolences and solidarity with the people of NY at this time".
"Eventually we actually saw on, we started watching the news we actually saw them catch him, 4 or 5 cops pick him up, carry him into a vehicle".
That network of barricades, though, is far from a complete defense. But an uncle was struck on the head by a pole dislodged by the vehicle, relatives said as they left the hospital where he was being treated. "It seems he was intoxicated we think, also supposedly he had a history of DUI's", said Gill.