FORT LAUDERDALE, Fla., Feb 22 (Reuters) - The armed deputy assigned to the campus of a Florida high school during a deadly shooting last week stayed outside the building during the attack and failed to engage the shooter, the county sheriff said on Thursday.

As a consequence, Scott Peterson, on duty as the school resource officer at Marjory Stoneman Douglas High School in Parkland, resigned from the department, said Broward County Sheriff Scott Israel, who earlier has suspended the officer from the force. He did not say if Peterson would face criminal charges.

Israel said he decided to suspend Peterson after viewing a video that showed the deputy did nothing during the rampage that killed 17 people. A former student Nikolas Cruz, 19, is accused of carrying out the attack with an AR-15-style assault weapon.

What I saw was a deputy arrive at the west side of Building 12, take up a position and he never went in, said Israel. The building is popularly known as the freshman building.

Israel said he would not release the video that shows Petersons actions at this time and may never do so, depending on the prosecution and criminal case.

(Reporting by Bernie Woodall in Fort Lauderdale; Editing by Tom Brown)