A grand jury in New York returned an indictment Friday against Trevor Bickford, charging him with a longer slate of offenses than before in connection with the New Year's Eve knife attack on NYPD officers.
The 19-year-old suspect has been charged with 18 criminal counts including three counts of attempted murder in the first degree in furtherance of an act of terrorism, and one count of aggravated assault on a police officer as a crime of terrorism.
Bickford was shot and arrested by officers on Dec. 31, not too far from Times Square, after he allegedly attacked three NYPD officers with an 18-inch kukri knife near West 52nd Street and 8th Avenue, outside the secure area that had been set up for New Year's Eve celebrations.
"All eyes are on Times Square on New Year's Eve and these charges reflect the seriousness of this alleged threat to the safety of our city and our officers," Manhattan District Attorney Alvin Bragg said in a statement.
The suspect will be formally arraigned on Feb. 1, according to the district attorney's office.
Bickford of Wells, Maine, carried out what a senior police official told ABC News was a terror attack likely motivated by Islamic extremism.
"I wanted to kill an officer in uniform," Bickford allegedly told police, according to the criminal complaint. "I saw the officer and waited until he was alone. I said 'Allahu Akbar.' I walked up and hit him over the head with a kukri. I charged another officer but dropped the knife and I tried to get the police officer's gun but couldn't."
Bickford's attorneys didn't immediately comment about the indictment. He is currently being held without bail.
Federal investigators allegedly had Bickford under their radar before the attack, according to investigators.
Thomas Galati, NYPD Chief of Intelligence and Counterterrorism told ABC News the FBI interviewed Bickford last month in Maine after his mother reported her concern that her son was possibly becoming radicalized. The FBI determined Bickford wanted to fight in Afghanistan and placed him on a federal watch list to prevent him from traveling overseas.
Bickford was able to acquire a large amount of cash, and ride an Amtrak train to New York City on Dec. 29, according to investigators.
ABC News' Josh Margolin and Miles Cohen contributed to this report.