A 45-year-old man suffered serious wounds after an apparent unprovoked attack by a suspect wearing an armored vest Wednesday afternoon on a VTA platform in San Jose, authorities said.

The assault at the Children's Discovery Museum Station happened about 1:15 p.m., when a suspect, later identified as Andrew Perez, 26, allegedly attacked the victim on the platform. Authorities said the two men didn't know each other, and it was unclear what provoked the attack.

A video of the assault was released by the Santa Clara County Sheriff's Department on Thursday. The video showed Perez approaching the victim, who was standing with his bike on the platform. Suddenly, the attacker throws the victim to the ground and begins punching and dragging him.

At one point, authorities believe a sharp weapon was used because the victim suffered a large gash on his forehead that required seven staples, and cuts on his elbow and wrist. The sheriff's office, however, didn't find a sharp weapon when they searched the scene.

When officers arrived, they found the victim covered in blood from his head to torso, the sheriff's office said. He was treated by emergency crews and hospitalized in stable condition.

The suspect had fled by the time authorities arrived but they found him barricaded at his home near the station. Perez was eventually arrested and booked into the Santa Clara County Main Jail on suspicion of crimes that include attempted murder and assault with a deadly weapon.

Jail records showed Perez is being held without bail and is set to appear Friday in Santa Clara County Superior Court.