I was walking from the National Gallery to the Botanic Garden and beside the reflecting pool was this big pile of horse poop. Three police officers on horses were leaving the scene of the crime. Was this a one-time occurrence? Did they just forget to bring their pooper scoopers with them? Or is it not their responsibilty, and their horses can poop wherever? Emilie Hyde, Arlington

Woodward and Bernstein followed the money. Answer Man follows the . . . well let's just say he follows his nose.

And he's not afraid to ask the tough questions. Questions like: What happens to the poop generated by the District's mounted units?

Without DNA evidence, it is impossible to say for certain to which local law enforcement agency these three particular horses were detailed. The Park Police, Capitol Police and D.C. police all have mounted units.

The Park Police have by far the largest contingent, reportedly more than two dozen horses, although in these perilous times the exact number is kept secret. The Capitol Police have six horses, and D.C. police have five.

If we assume there are roughly 30 horses on patrol at any one time in the Washington area, and that each horse generates about 40 pounds of manure a day, that's a daily total of 1,200 pounds of waste that has to go somewhere.

While the D.C. Code stipulates that carriage horses must wear diapers -- "constructed of a sturdy material and . . . properly fitted to the horse to ensure comfort" -- it is silent on the subject of police horses. Officer Michael Lauer of the Capitol Police said they looked into getting diapers for their horses but "that was something we opted not to use."

Instead, the officers themselves are responsible for cleanup, carrying plastic bags for that purpose. "If it's in a high-volume pedestrian area, they would get off the horse, collect it, then dispose of it in a trash can," Officer Lauer said. If it's not in the path of pedestrians, then they leave it.

"We haven't received many complaints about cleanup or the smell associated with the animals," he said. "Our officers and riders have been very diligent about the cleanup." (He said that one has even trained his horse to go in the same, out-ofthe-way place each day.)

D.C. police mounted officers handle it a bit differently. Officer Tom Stewart said, "If we're out riding and the horse has a drop, we just make a note of it. Before we leave the beat, we ride back with the truck and pick it up."

"The drop" might hang around for a while, but it is cleaned up eventually. If it's on a sidewalk, the officer dismounts and kicks it into the street, Officer Stewart said, a good reason to wear those big, shiny boots.

Lt. Jon Pierce, commander of the Park Police's horse-mounted unit, said that since most of their patrols are in natural areas, such as Rock Creek Park and the C&O Canal, they usually just leave it where it falls. "It's biodegradable," he said. "It fertilizes the soil."

But if a horse should do its business in front of a memorial, park service maintenance personnel clean it up.

Michael Tilton, a Butler County, Ohio, horse-patrol officer who runs the Mountedpolice.com Web site, said most officers across the country either: leave it where it is; do as the Capitol Police do and scoop it into bags; or, like D.C. police, remember where it is and swing back later with the trailer and shovel it in.

"Once, we actually had a homeowner come out with a shovel to get the manure to put on his flower bed," he said.

Officer Tilton said that when he rode in President Bush's inaugural parade, he was amazed to see two men positioned behind each mounted unit, one with a pitch fork and the other with a wheeled garbage can, sanitizing the street as they walked along.

Mary Myers of the District's Department of Public Works, said: "As a general day-to-day function, we wouldn't be detailed specifically for horse poop. But during the inaugural parade or the Reagan funeral or circus elephants coming through town, we would be."

K-9 No. 2

I know what some of you are thinking: So that's the story with police horses, but what about all the police dogs who have to do their duty?

Russ Hess, executive director of the Ohio-based U.S. Police Canine Association, said most officers carry plastic bags in their trunks and just pick up the dog doo as would any other owner. Then they dispose of it in the regular trash.

"They can pretty well predict when that's going to happen," Russ said. "[Dogs are] regular, like a person."

The dogs who protect the White House -- checking incoming vehicles for dangerous cargo -- have a special place for their waste. It's a brown trash can near the Ellipse, at 17th and E streets NW. The can is like others in D.C. parks, but it has a lid and a sign that says: "K-9 Usage Only."

Secret Service spokesman Tom Mazur confirmed that the can is intended for Secret Service use but said it's okay if regular citizens needed a place to drop their doggy doo.

Said Tom: "Our agents did say that sometimes when there's warmer weather, depending on the direction of the wind flow, not too many picnics or blankets are laid down there."

Have a question about some aspect of the Washington area? Ask Answer Man. E-mail answerman@washpost.com, or write John Kelly, The Washington Post, 1150 15th St. NW, Washington, DC 20071.