Authorities release new details about the devastating shooting at a South Florida High School Wednesday.

The Broward County Sheriff said the suspected shooter bought a drink at a Subway and stopped at a McDonald's in the hour after the massacre of 17 people.

The Sheriff said the suspect was confronted by a police officer and taken into custody about 40 minutes after leaving the McDonald's and more than an hour after the first were fired.

Officials said the shooter was dropped off at the high school by an Uber driver.

A report from the Sheriff's Office said 19-year-old Nikolas Cruz confessed to investigators that he was the shooter.

The report details how Cruz dropped his gun and took off his vest to blend in with the crowds of students fleeing the school.

Authorities said Cruz used an A-R 15 rifle he purchased legally about a year ago and overall, the investigation is still very much fluid.

"Moving forward, we will continue to gather all information about the subject as we try to identify...any other indicators that may be out there,” said FBI Miami Special Agent in Charge Robert Lasky.

Earlier in the afternoon, Cruz was arraigned on 17 counts of premeditated murder.

A judge ordered he be held without bond on the charges.