MANSFIELD (CBS) — While students in Mansfield were enjoying February vacation week, police officers filled a school’s hallways to train for an active shooter situation.

“We simulate everything from the beginning: from the call, to the response, to the staggered response time, to the entry point,” said Mansfield Police Chief Ronald Sellon.

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Police at Jordan Jackson Elementary School went through force-on-force training and used high-speed paintball guns with fake bullets during their simulation Wednesday.

“It’s very difficult, during a critical incident, when stress level is real high, we find motor skills go out the window and you’re relying on ‘what I’m supposed to do right now?’ It’s much easier to fall back on something you’ve done consistently four times during the course of the year,” said Sellon.

He also said all 36 of the department’s officers participate.

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Police are required to do daily, random walk-throughs at all of the Mansfield Public Schools.

Superintendent Teresa Murphy said police are training faculty and staff too.

“This year we’ve brought it to a different level. The police chief has offered to provide what is called 4L’s training, it is ‘locate, lockdown, leave, or live,'” said Murphy.

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The school district is looking to find the money for another school resource officer. They currently have one.