There are those who believe military operations have little in common with police operations. But these are people who envision all military engagements as the open field battles of World War II movies or the jungle fights of Vietnam War news footage. Contemporary U.S. troops are often called upon to engage the enemy in urban combat and police can learn a lot from their experiences.

That was the message of Staff Sgt. David Bellavia's keynote presentation at this year's POLICE-TREXPO East. Bellavia, author of "House to House: An Epic Memoir of War," gave a stirring presentation to the audience on close-quarter battle in the Battle of Fallujah. The Army veteran was awarded the Silver Star and Bronze Star and nominated for the Medal of Honor for valor in that fight.

Bellavia minced no words in his descriptions of the grisly nature of close-quarter battle. "What you are going to see in a close-quarter fight is ghastly and horrific. Prepare yourself for it," he told the POLICE-TREXPO audience.

Detailing the actions that led to his citations, Bellavia explained that he was ordered to take his squad of soldiers and clear an enemy-held block of houses. His squad quickly found itself in a hornet's nest of enemy fire. The battle for the house was so vicious that Bellavia was forced to engage one jihadist in hand-to-hand combat. He killed that jihadist with a Gerber folding tactical knife, preventing him from detonating a bomb composed of propane tanks. "In a fight like that everything on you is a weapon," he said.

Bellavia also discussed specific tactics and maneuvers to avoid in close-quarter operations, but he added that once the battle begins things change very rapidly. "It's all about thinking outside the box," he said. "You have to prepare for the craziest thing to happen."

Related:

POLICE-TREXPO 2011: Overview

POLICE-TREXPO 2011: Grossman on Media Violence

POLICE-TREXPO 2011: Tactical Gear