The training lasted two days, taking ten Soldiers and six Marines through multiple scenarios.

They learned weapon positioning, proper footwork, and communication skills. They performed discrimination drills by entering a room full of cutout targets, from innocent civilians to actual threats. In a split second, they had to make life-and-death decisions at the pull of a trigger. They ran dry-fire drills, clearing rooms as two and four-person teams. The training culminated with four simulated scenarios with increasingly complex threats.

"The Army Reserve has taken a very proactive approach in enhancing the safety and security of our Soldiers," said U.S. Army Reserve Maj. Matthew Dick, executive officer for the 607th Military Police Battalion based out of the Grand Prairie Armed Forces Reserve Center.

Dick is also a SWAT team member with the Grand Prairie Police Department, which led the training. It provided instructors and equipment to help make the event a success.

"They [training attendees] now have a common knowledge of what their capabilities and tactics are in response to an active shooter situation," said Dick.

What began as a fast-paced introductory course at a repurposed building, culminated in a growing relationship between all three entities. Though they wear different uniforms, they share the same commitment: serve and protect the United States and its citizens.

"I don't think you can put that into words-knowing that you help save lives, that's what we do-in the military and in the police department, that's our job," said Officer Nathan Lawless, Patrol/SWAT, GPPD.

The U.S. Army Reserve published a directive in January, requiring armed Soldiers and increasing security measures at stand alone facilities following attacks in 2015.

This training is a direct result of that enhanced force protection and physical security directive, said Dick.

At the beginning of day one, the groups gravitated to like uniforms. "We started out being just Marines and Army, and then we blended it together," said Sgt. Adam Rendon, property book noncommissioned officer for the 607th MP Bn. As the day and training progressed, comfort levels rose and the two groups blended.

"It's actually really cool to work with our brothers and sisters in arms. It's really nice to interact with different services and get a feel for how they operate because we do share a base," said Marine Sgt. Steve Cunningham, cyber chief, 2nd Battalion, 14th Marines.

The police officers taught the trainees their best practices and tailored the training to best benefit the group. The collaboration allowed the service members to learn from years of SWAT, patrol and civilian law enforcement experience.

Sgt. Jillian Carlino, training noncommissioned officer for the 607th MP Batt., said that training with the local law enforcement has made her a more confident noncommissioned officer and military police. It will give them a more secure presence in the community, she said.

The students didn't just learn from the officers. They also learned from each other. Both Marines and Soldiers talked through scenarios and strategized tactics as they went room by room through the building. Learned methods were passed around from group to group as the teams were shuffled.

"It was a great learning experience," said Rendon, who joked that he learned through a great deal of mistakes during the scenarios, but ultimately feels more prepared as a result. "We don't want anybody to get hurt, whether it be Soldier or Civilian, which is the whole concept of this training."

The possibility of threats at reserve centers have become a reality in recent years. These skills allow the men and women at installations to prepare for those situations.

"The Army Reserve always has, always will have Soldier safety and security as a top priority," said Dick. "They now have a common knowledge of what their capabilities and tactics are in response to an active shooter."