The night sky in Downtown Nashville explodes with shimmering fireworks and special effects lighting from outdoor concert stages. Electrified by country music, the summer evening is dampened only by the heavy-as-a-wet-wool-blanket Tennessee humidity. Fortunately for officers of the Metropolitan Nashville Police Department, residents are quick to offer up sloshing, thirst-quenching buckets of water … for their horses.

The CMA Music Festival-a three-day Country Music Association extravaganza that draws some 130,000 fans each June-is but one event uniquely suited to the Metro Nashville PD's popular Horse Mounted Patrol Unit. The six-person, 12-horse unit also works sporting events and other gatherings requiring pedestrian traffic control, and patrols the downtown entertainment district, malls, and city streets on a daily basis.

"Horses and police work are the two things I love most, and my job encompasses both of them," says Officer Karen Krause, a Houston native whose granddaddy ran a cattle ranch in the Lone Star State back in the 1950s. A 21-year veteran of MNPD, she has been a member of the unit since June 2001.

Like the other mounted patrol officers, she rides a Tennessee Walking Horse, a breed well known for its even temper and smooth gait. Krause's favorite mount is Sabre, a black gelding and former U.S. Army horse from Fort Riley, Kansas, who still bears the government-issue brand of "U.S." on his muscular left shoulder.

"He's like a light switch," Krause says. "He knows when to just stand around and have kids hug his legs. But when it's time to go, his ears perk up. He loves breaking up fights; I can feel his heart beat through the saddle."

All of MNPD's horses are donated, and most come from the horse breeding industry. Each officer is responsible for two horses, which are stabled at a Tennessee Department of Agriculture barn 10 miles from downtown Nashville. While on patrol, officers wear specialized apparel, including riding breeches and equestrian helmet. Horses are outfitted with their own safety equipment, including reflective yellow ankle wraps and small red LED flashers mounted on the back of the saddle.

All the horses-Storm, Peacekeeper, Justice, and the others-are geldings, as well.

"It just seems to work out better," Krause notes. "They keep their mind on work."

That single mindedness is essential when dealing with unpredictable policing environments that would terrify most horses. In the crowded downtown area, traffic generally moves no faster than 25 mph, and the police horses have even willingly ridden up beside suspected DUI vehicles to pull the driver over.

"This [breed of] horse loves to please," says Sgt. J.D. Harber, who oversees the unit. "I can stand on the center line, in the middle of the street, and direct busy traffic, and never pick up the reins. The horse just stands there, and I move him with my feet and legs. Once the officer develops a bond with the horse, [he] will do anything in the world for you."

Harber's favorite mount is Joe, a glossy chocolate bay whose officially registered "civilian" name is Solidarity's Smokin' Joe. The police horse, which Harber has ridden for the past seven years, has accompanied him into rock-throwing mobs, searched for lost children, and even helped "talk" a jumper down from a bridge. Harber persuaded the distraught man to pet the horse, moving him away from the railing and certain death. For that, Joe earned an official mayoral decoration for heroism.

Tourists and kids are especially drawn to the horses, and Nashvillians of all ages seem to "perceive us as being more friendly," says Krause. "They don't have that automatic defensive reaction. They must feel we're more human because we love horses."

The animals' power and size also benefit ground-bound officers.

Krause and another officer were on the scene one night when promoters drastically oversold a high-dollar concert, then refused to refund ticket holders' money. The angry crowd eventually swelled to 200, and began fighting in the streets. Foot patrol officers, rushing in to make an arrest, were joined by the horses, which kept the crowd at bay.Then, with the police horses "parting the sea" to safety, officers and their prisoners followed the animals back out.

"We can move many, many people with one horse," Harber says. "In some cases it's the intimidation factor. People may not respect an officer, but they may respect that 1,300 pounds of horse, and don't want to get stepped on. The other is information. We're up taller, and people [in a crowd] can see the information we're giving them."

MNPD's Horse Mounted Patrol Unit, formed in 1998, is a full-time operation. Last year, in addition to routine patrol duties, officers and their mounts worked more than 600 assignments and events, including NFL Tennessee Titans football games, funerals for fallen police officers, and visits to retirement homes and other community events. That resulted in contacts with more than 2.5 million people, Harber says.

Officers may apply for a position with the unit after three years of service with the department, but only the most dedicated make the cut. Applicants aren't required to have a riding background, but do need to demonstrate passion for the assignment-and for the horses themselves. Some mounted patrol officers now in the unit were regularly visiting the barn well before being invited to join. Others have spent off-duty time at the barn to care for an ailing horse.

"That's the whole key," says Krause, who has herself stayed overnight when Sabre fell ill. "At the end of your shift, your main objective is to come home safely-and with us, it's us and our horse."

Bryn Bailer, a former newspaper reporter, is a contributing editor for Police. By night, she is a member of the Tucson (Ariz.) Police Department Communications Division.