The suspect in Tuesday’s subway attack in Brooklyn appears to have posted dozens of videos on social media in recent years — lengthy rants in which he expressed a range of harshly bigoted views and, more recently, criticized the policies of New York City’s mayor, Eric Adams.
The man, Frank R. James, 62, has addresses in Wisconsin and Philadelphia, the police said.
Two law enforcement officials said that a credit card with Mr. James’s name on it had been found at the scene of the shooting, as had a key to a van that Mr. James had rented, along with a Glock 9-millimeter handgun, three ammunition magazines, a hatchet, fireworks and a liquid believed to be gasoline.
It appeared that Mr. James had rented the van in Philadelphia sometime over the last several days, driven it close to the subway line where the attack occurred and abandoned it there, one official said. The police found the van eight hours after the attack.
As the hunt for Mr. James continued, New York police officials and their federal counterparts asked that people share cellphone video from the shooting site or elsewhere that might help bring the manhunt to a swift conclusion, and sent an emergency alert on Wednesday morning asking residents to direct any information about Mr. James to the N.Y.P.D. tip line at 1-800-577-TIPS.
The authorities offered up to $50,000 in reward money for information leading to the arrest and indictment of Mr. James.
The police also released a screenshot of Mr. James taken from a YouTube video posted by a channel belonging to the username prophetoftruth88.
The videos featured a man — who appeared to be the same man in a picture released by the police — delivering extended tirades, many of them overtly concerned with race and violence, often tying those subjects in with current events, including the Russian invasion of Ukraine and the policies of Mr. Adams. Two law enforcement officials said that Mr. James was the person featured in the channel’s videos.
In a video posted to YouTube on March 1, the person featured in the video criticized Mr. Adams for recently announced policies addressing public safety in the subways, which focused on homeless people.
Ms. Sewell said at the news conference Tuesday that Mr. Adams’s security detail would be increased in light of the videos.
Another video on the channel, posted in 2020, appeared to have been taken in New York’s subways. In that video, the person holding the camera simply trains it on a crowded subway car.
Officials said that consumer-grade fireworks, gasoline and two unused smoke grenades had been recovered from the scene of a shooting, and a photograph circulated on social media on Tuesday appeared to show the fireworks, along with other material.
William Weimer, a vice president at Phantom Fireworks, said that a man named Frank James from Milwaukee had purchased several brands of the fireworks seen in the photo from the Phantom Fireworks’ showroom outside of Racine, Wis., last June.
Andy Newman and Ashley Southall contributed reporting.