The man who drove his car into a crowded sidewalk in Times Square on Thursday was high on synthetic marijuana, known on the street as K2, according to ABC News.
Richard Rojas, 26, plowed down three city blocks, killing an 18-year-old woman and injuring at least 22 others in what appears to have been a drug-fueled rampage.
Rojas, a Navy veteran from the Bronx, has been arrested twice in the past for drunken driving -- in 2008 and 2015.
There was "no indication" it was an act of terrorism, Mayor Bill de Blasio told a news conference at the scene.
Authorities investigating the scene found materials that indicated Rojas has an interest in Scientology. He also told police that "This was the last day on Earth," according to New York Daily News.
K2, also known as Spice, has been known to create "zombie-like" symptoms in some consumers and has been responsible for hundreds of overdoses in the New York City area in recent years, including more than 130 people in a span of a few days in 2016.
The drug is typically a mix of herbs and chemicals.
(Reuters contributed to this report)