The man who killed two young students in a school in New Mexico pretended to be a student to enter and go unnoticed in their corridors, according to authorities. It had attracted the attention of researchers a year ago.

William Atchinson entered the school and went to a bathroom on the second floor to prepare. His plan was to shoot at a classroom and then commit suicide.

But his plan was altered when Hispanic student Francisco I. Fernandez entered the bathroom, authorities reported. When she found him, she shot him dead, just like Casey J. Martinez, who ran into her in the hall when she was leaving and killed her.

After that, the attacker walked through the halls, shooting randomly until he committed suicide. “It’s a cowardly act,” said San Juan County Police Chief Ken Christesen.

Atchinson had no criminal record. His only encounter with the police, says the AP agency, was when he commented in a video game in 2016 what weapons could be used in a large-scale shooting attack. The FBI said that this message caught the attention of the agents and that’s why they talked with him at his home in Aztec. There he confessed that he had no intention of committing a shoot-out and that he only liked to provoke.

Aztec is a small town in San Juan County, in northwestern New Mexico, about three hours from Albuquerque.