The driver of a vehicle that tore through crowds wreaking havoc in the heart of New York City has been charged with murder, police said Thursday (May 18) night. Richard Rojas, 26, was arrested after his maroon sedan jumped the curb and hit 23 individuals in Times Square, killing Alyssa Elsman, an 18-year-old tourist from Michigan. Rojas was charged with second-degree murder, 20 counts of attempted murder, and five counts of aggravated vehicular homicide, according to a press release from the New York City Police Department (NYPD). Following his arrest shortly after the crash at around noon, Rojas was transported to a testing facility to determine whether he had drugs or alcohol in his system. The U.S. Navy veteran had been arrested on two prior occasions for driving while intoxicated. Law enforcement sources told local media that Rojas tested negative for alcohol but positive for drugs, with some reports suggesting he was under the influence of a dissociative -- causing feelings of detachment from reality -- drug known as PCP. Officials were quick on Thursday to dismiss the possibility of a terrorist attack, describing the tragedy as an isolated incident. An investigation is underway, according to the NYPD.