Juan Barrientes was behind the wheel of his squad car, chasing a wanted man armed with a shotgun. Somehow, the man was managing to fire rounds through his blown-out back window and drive at the same time.
Barrientes, then a DeKalb County deputy, could hear buckshot bouncing off his cruiser. His hands and legs were shaking. He knew he needed to calm down.
So he started focusing on his breathing.
In through the nose, two, three, four. Hold, two, three, four. Out through the mouth, two, three, four. Hold, two, three, four. Repeat.
His stress level began to drop. He started to the see the big picture, figuratively and literally. His vision widened. He checked his mirrors.
What Barrientes did that day is known as tactical or combat breathing, a simple tool that some police officers have been using for years to help keep a cool head in an intense situation.
"Had I not done the combat breathing," he said, "I don't know if I would have been either effective or survived that incident."
The chase eventually ended, and the fleeing man was caught. That happened in 1998.
Barrientes is now a training officer with the Fort Wayne Police Department, and he finds himself regularly teaching officers how and when to control their breathing.
"Through combat breathing, what you can essentially do is slow your heart rate, lower your blood pressure, calm yourself down and think," he said.
Lately, tactical breathing has been championed by Lt. Col. Dave Grossman, a retired West Point psychology professor who travels the country teaching the technique to tens of thousands of police officers, military members and others.
Grossman is quick to point out that harnessing one's breathing to conquer stress, fear, pain or anger is nothing new. It has been applied in various realms, such as martial arts, sharpshooting and Lamaze, for generations.
He credits Calibre Press, a publishing house in California, with pioneering the use of tactical breathing in police work through its Street Survival seminars for officers in the 1990s. Barrientes said he learned the technique in 1995 when he attended the Indiana Law Enforcement Academy in Plainfield.
Grossman said his contribution to the field of tactical breathing has been explaining how it works. In his book, "On Combat," he compares tactical breathing to putting "a leash on the puppy." The puppy in this case is our instinctive reaction to stress, also known as the flight-or-fight response.
By taking charge of your breathing - a bodily function usually done unconsciously - you can take charge of your puppy, according to Grossman.
"What you're doing is gaining conscious control over the unconscious part of your body," he said.
This act of seizing control, along with sending oxygen to your body and preventing hyperventilation, is the reason the technique works.
"It comes back to Mama saying, `Take a deep breath,' " Grossman said.
While law enforcement agencies in the Fort Wayne area have fully embraced training officers in tactical breathing, other local first responders emphasize breathing in less formal ways.
Mike Gillespie, a spokesman for the Three Rivers Ambulance Authority, said it's rarely an issue for medics to overload on stress. But, he said, new medics are taught something like tactical breathing.
"If they do get excited, we explain to them to slow their selves down and slow their breathing down," he said, adding that this helps them quickly process information.
The Fort Wayne Fire Department has its firefighters practice controlled breathing, among other skills, on what's called a "confidence course," Assistant Chief Ron Privett said.
Wearing all their gear, including an air tank and mask, firefighters complete a maze of events crammed into a small, cinder- block building on the department's training grounds east of downtown. The events are done in pitch-black conditions, and they simulate search-and-rescue scenarios such as wriggling under a tangle of electrical wires or slipping between stud beams separated by less than 15 inches.
One goal, Privett said, is for firefighters to finish the course before using all the air in their tanks. Good physical fitness and the ability to control breathing can extend a firefighter's air supply by several minutes - time that becomes vital inside a burning building, he said.
Firefighters who become too worked up while going through the course are reminded to slow their breathing. But the department is not to the point where it specifically instructs recruits in tactical breathing, he said.
Along with training police officers, Barrientes is one of eight snipers on the city's SWAT team.
As part of the test to become a sniper, officers have to run 400 meters and then shoot accurately. To do this, they use tactical breathing and pull the trigger during a "respiratory pause" after exhaling, Barrientes said.
A sniper lying down and taking a shot after some controlled breathing is not typical of most police shootings. Usually, the officer has little time to react, let alone time to complete a tactical breathing cycle, before firing, he said.
Although, after a police shooting, tactical breathing can help calm an officer. And during a prolonged physical fight or gunbattle, it can allow an officer to maintain complex motor skills, such as the action of running, crouching, aiming and shooting a gun, Barrientes said.
Beyond the life-and-death situations that face police officers and combat troops, a variety of other applications for tactical breathing are gaining traction.
Veterans use it to cope with post-traumatic stress disorder. Police officers use it to stay level-headed on the witness stand while facing aggressive cross-examination from defense attorneys.
Students have used it to subdue test anxiety. Car-crash victims have used it to keep from going into shock. It's used by pilots, free-throw shooters and heartburn sufferers alike.
There are even apps that give instructions on tactical breathing.
"It's taken off like a grassfire," Grossman said. "To be able to control our fear, to control our anger, to control our pain is just a powerful, powerful evolutionary step forward."