MARIETTA — During their second lockdown drill this school year, Marietta High School students, faculty and staff acted Wednesday as if a real shooter were on campus.

Marietta Police Department spokesman David Baldwin said the exercise was called “Out of Sight, Out of Mind.”

“This has been proven to be the most efficient manner to keep them safe until law enforcement can arrive and engage the shooter,” he said.

It was designed to deprive an armed intruder of an easy target, Baldwin said.

“We want to go from a vibrant classroom environment to a desolate no-man’s land,” he said. “The shooter will typically bypass that area.”

The drill comes a month after the Dec. 14 mass shooting at Newtown, Conn., in which an intruder killed 20 students and six adults. Baldwin, however, said the drill is a regularly scheduled event.

“This is something we have done for years,” he said. “It has more impact now due to different events. The students are able to put the importance of this event with the state of affairs of things that have happened in the U.S.”

School staff and faculty attended a training session earlier this month to prepare, while students had been briefed this week.

“For the last two days, we have been reviewing safety protocol procedures for an intruder drill,” Principal Leigh Colburn said.

Homeroom teacher Jennifer Santi told her 11th graders they were “well-versed” in what to do.

“Remember, line of sight is from the edge of that door,” she said about the view from the door’s glass panels, which were covered with paper, across to the two farthest corners of the classroom. “Take all your stuff with you. We want to give the illusion the room is empty.”

Neither students nor their cell phones could make any sounds.

“We’ll be silent as mice,” Santi said.

Then the signal came.

“The building has been raised to Safety Level Red,” Colburn said over the intercom.

Santi locked the door and turned off the lights.

The students grabbed their knapsacks, headed for the corner of the classroom closest to the door and stood or sat motionless.

It took about a minute to complete the actions, followed by about five minutes of waiting, interrupted only by an outsider trying the door handle unsuccessfully.

Afterward, student Nick Morgan, 17, said he felt safer.

“I think that it’s good to know that not just I know, but so does everybody else,” he said. “Really, what would keep us safe in the event that there was an intruder would be that everyone knows the drill.”

Nick said the point was to reach a common goal during a tense situation.

“It’s all about getting us out of the way, out of harm’s way, and then (first responders) can come and take care of it,” he said.

Shayna McClure, 16, said the students’ training helped them do their part.

“We knew there was going to be a drill. We’ve been talking about what to do and how to prepare,” she said.

Trinity Martell, 16, said the safety procedures gave her a sense of security.

“I was very comfortable. It’s easier for me to be clumped up,” she said about huddling with her classmates. “I feel more protected.”

Afterward, Baldwin said students, teachers and administrators fulfilled the drill’s goal.

“They did great,” he said. “The hallways were completely cleared.”

Baldwin said other Marietta schools will have their own lockdown drills this semester.