NYC subway shooting suspect Frank James was known to FBI

A federal law enforcement source told Newsweek the suspect was previously known to the FBI, having been entered into the Guardian Lead system in New Mexico. 

The system is the FBI's way of coordinating information from other law enforcement partners about potential terrorism-related threats and suspicious activity reports. He was cleared after multiple interviews in 2019. 

The federal law enforcement source said that he is believed to have driven to New York from New Mexico.