A person making multiple phone call threats to Marshall High School and the Marshall ISD administration building led to the district locking down all nine of its campuses for more than an hour on Thursday while police investigated.

Marshall ISD spokesman David Weaver said the four threatening calls all came from the same caller.

At the time of this publication Thursday evening, no arrests had been reported.

“We did receive a threat this morning, three calls made to Marshall High School and one made to the administration building,” Marshall ISD Superintendent Jerry Gibson said Thursday. “Immediately we put the campuses on lock down. No one entered the buildings and our police were on point here within 30 seconds of the phone call. Our entire police department was here within five to seven minutes. All students were safe at all times and we took every precaution.”

Gibson said students were in lock down which means students were held within the classrooms they were in and not allowed to move throughout the campus. Also during lock down, no one is allowed to enter or leave the premises.

The lock down began just after 11 a.m. Thursday. District campuses were then moved to a “soft” lock down about 11:30 p.m., allowing them to move throughout the campus and resume their class schedules, though no one could still leave or enter the campus. The lock down was completely called off about 12:30 p.m. Thursday.

Gibson said the lock downs on Thursday were necessary to keep students safe while law enforcement investigated the threat.

“I know as a parent, it’s very frustrating and it’s very hard but it’s the best thing we can do to keep our students, your children safe,” Gibson said. “There was never any harm and no one entered the building or the campus. We are investigating all leads at the time and if something turns up, we will as a school district prosecute anyone to the full extent of the law.”

Gibson said Marshall ISD police remained on district campuses throughout the school day on Thursday and anyone who came on campus was required to show valid identification to get on campus.

Marshall ISD Police Chief Joe Arledge developed a crisis response plan for the district and each of its campuses last year.

The plan Arledge devised, with the help of city and county first responders, proved to be so comprehensive that Harrison County Sheriff Tom McCool later instructed his department to implement a version of Arledge’s plan for other Harrison County school districts.

“With all of the recent events in our nation, like the school shootings, my thoughts were, if we had an organized plan, that everybody knew what they were supposed to do, then it wouldn’t just be mass chaos should something happen,” Arledge said last year. “If, God forbid, we have an incident on campus and we have 40 to 50 officers show up from different agencies and there’s no plan, it would be chaos. This plan gives everybody an idea of where they need to be and what they need to be doing.”

The plan consists of immediately addressing the threat, including securing students and terminating the threat as soon as possible, as well as outlining which agencies will handle what and where command posts will be set up for media and other groups, Arledge said. Then comes the plan for after the incident, which includes a full investigation being conducted and completed and the school being deemed safe for operation again.

The district’s communication team would be responsible for notifying parents, after students are secured and the threat is addressed, Arledge said.

Marshall ISD posted several updates on its Facebook page on Thursday as the lock down status changed and sent out an all call to parents shortly after the first lock down began.