FORT MCCOY, Wis. -- Lightning cracked and thunder rolled as the skies opened on Fort McCoy, where the 351st Military Police Company from Ocala, Florida bunkered down in an imitation Middle Eastern city to wait out the storm on June 22. Fort McCoy was expected to get over a foot of rain within an hour.

The company was participating in Guardian Justice, a two-week exercise focusing on military police tactical skill sets, when the storm broke over its training. Much like the weather, unexpected changes can occur in combat situations at any moment -- and U.S. Army Reserve military police, also known as MPs, are prepared for those contingencies through the Guardian Justice exercise.

This year, the 300th MP Brigade, based out of Inkster, Michigan, hosted the Guardian Justice exercise, which included the participation of 16 units and assistance from two support companies. Maj. Angela Meyer is in charge of the training and planning for Guardian Justice, and structured the training upon the idea that MPs should be ready for any environment combat brings their way. As the world changes and enemy threats become more complex, the MPs continue to train hard to be the most multifunctional corps in the Army, making them the 'Force of Choice.'

"Guardian Justice focuses on the individual, team and squad levels," said Meyer. "In years prior, training focused on detainee operations, but recently, we've added combat support, which means we're getting back to the basics of field environments. This means setting up tents, using our radio communications instead of cellphones, using maps instead of CPOF (a glorified G.P.S.), and we're using our gas masks and MOPP 4 (a suit that protects from chemical, biological, radiation and nuclear contamination)."

Traditional detainee operations training also took place, including biometrics, the in-processing and tracking of prisoners of war, and a less-than-lethal class, which consisted of combatives and Taser qualification. Guardian Justice also provided training in convoy operations, land navigation, reflexive fire and military operations in an urban terrain.

The 361st MP Company out of Ashley, Pennsylvania, recently returned from a detention operations mission in Guantanamo Bay, Cuba. For the 361st, the combat support element of the training is a whole new ball game.

"We're proficient in detainee ops, but now we're transitioning into a combat support unit," said Staff Sgt. Stephen Levey, a Philadelphian and platoon sergeant with the 361st. "Even though they are both MP functions, they are completely different. With my new responsibility as a platoon sergeant, I'm learning what it takes to successfully move a fully-manned convoy, even when Soldier's get pulled to complete other tasks."

Combat brings on unfortunate events, and should anything unexpected happen, Soldiers of all ranks can be ready and capable to step up to the challenge.

"I went to convoy training and at one point I was assigned convoy commander," said Pvt. Christopher Fongemie, an MP with the 354th MP Company out of St. Louis, Missouri. "I learned how to control everyone, radio up to the TOC (tactical operations center), call EOD (explosive ordnance disposal) for IEDs and make sure everyone is in line and moving properly."

The knowledge sharing that Guardian Justice facilitates is the key to unit cohesiveness. There is an intangible growth of trust and sound decision making that is weaving its way through the ranks of the 300th.

"Battalion commanders are only as strong as their subordinates, and this training is tremendously helping to build that trust between them and their junior leaders," said Maj. Julius Austin, the operations officer for the 336th MP Battalion out of Pittsburgh. "There's new commanders and new Soldiers who are all getting mentored by their leaders and learning how to make critical decisions."

For new Soldiers like Fongemie, building trust is critical for unit cohesiveness.

Fongemie's platoon sergeant, Staff Sgt. Max Boyd, says there's nothing more important than knowing and being familiar with the people you deploy with -- and you only get there by training with them.

"I have a lot of re-classes and Soldiers who are fresh out of basic training," said Boyd. "We're getting in a lot of reps out here and I'm seeing them grow from the individual, to the team, squad and company element."

"We get in this mindset that we are going to be fighting a certain type of army in a specific place, when the reality is we don't know where we're going next, and we don't know what's going to happen," said Meyer. "When we train for specifics, we can forget the unexpected can happen anytime."

If the mission calls for U.S. Army Reserve MPs to perform detainee operations, tactical convoys, or don their wet-weather gear, they will be waiting, willing and ready.