An unarmed campus monitor told detectives in a sworn statement that he saw Nikolas Cruz "beelining" onto a South Florida high school campus, moments before opening fire in a mass shooting that killed 17 people, the Sun-Sentinel reported. The monitor, however, later disputed what he told investigators under oath, the newspaper reported.

Andrew Medina, a baseball coach at Marjory Stoneman Douglas High School, was driving his golf cart around campus and unlocking gates 20 minutes before dismissal on Feb. 14. He told investigators that he saw Cruz, a former student, head hung low, carrying a duffel bag and wearing a backpack, walking onto campus.

“Crazy boy. That’s crazy boy,” Medina told detectives in a sworn statement obtained by the Sun-Sentinel.

Medina said he saw Cruz, 19, leave a gold-colored Uber vehicle and stride toward the building where the shooting would occur.

“He’s beelining. He’s got his head down. He’s on a mission, you know. He’s on a mission,” Medina later told investigators.

According to Medina’s sworn statement, he radioed ahead to David Taylor, another campus monitor assigned to that building, that a suspicious person was approaching. Medina told Taylor to “be careful,” but told detectives that he did not realize that Cruz was carrying a gun.

Cruz began running when he noticed Medina heading toward him, and then went into the building.

In less than a minute, Medina said he heard “the first bang, like ‘pow,’” the Sun-Sentinel reported.

“I’m telling you I knew who the kid was,” Medina, 39, of Coral Springs, told investigators, according to the documents obtained by the Sun-Sentinel. “Because we had a meeting about him last year and we said, “If there’s gonna be anybody who’s gonna come to this school and shoot this school up, it’s gonna be that kid.’”

On Wednesday, Medina disputed what he told investigators while under oath. He told a reporter that there was never a meeting identifying Cruz as a potential school shooter, he didn’t recognize Cruz specifically and he saw him arrive at the school from a distance of about two football fields.

At the first sound of gunfire, Medina told detectives he considered reporting an emergency code -- a warning that a shooter was on campus -- but hesitated, the Sun-Sentinel reported.

Hours later, Medina second-guessed himself as he talked to detectives.

“Now I really wish I would have stopped him before and we would have saved all this, but it really wasn’t nothing I could do about that,” the Sun-Sentinel reported, citing Medina’s sworn statement. “I was just doing my job, what they train us to do, you know.”