The back door of a Pitt police car swings open, and Officer Riggs leaps out and lands on the… The back door of a Pitt police car swings open, and Officer Riggs leaps out and lands on the pavement. Officer Dave Nanz, Riggs’ handler, is holding the end of Riggs’ black leash. Riggs tries to dart forward, and Nanz yanks the leash to hold him back. Riggs is ready to go to work.

Riggs, a slender, 3-year-old black Labrador, is the Pitt police’s bomb-sniffing dog.

Together, Riggs and Nanz make up the Pitt police K-9 unit, which responds to threats and conducts precautionary sweeps to look for explosives on Pitt’s campus. In order to stay sharp for this task, Riggs and Nanz must train constantly. That’s what they’re doing on this hot July day.

They’re at Pittsburgh International Airport, where they complete training sessions once a week along with other K-9 officers who work for Allegheny County police and Pennsylvania state police. Right now, the officers are doing luggage sweeps, in which the dogs have to identify suitcases that contain ingredients used to make explosives.

Four other dogs have already completed the activity, and now it’s Riggs’ turn.

Riggs and Nanz enter a door into one of the airport’s baggage claim areas, where 35 suitcases form a row that stretches across the room. Inside, Riggs and Nanz start on the left end. Nanz snaps his finger over the first suitcase. Almost touching his wet, black nose to it, Riggs circles the suitcase clockwise to the opposite end, then turns around, circles it counterclockwise and moves on toward the next bag, all in one fluid motion.

Suddenly, Riggs skips a suitcase and runs straight to a dark green suitcase that is next in the line. He seems to be on to something. After circling the bag, Riggs sits down next to it and looks up at Nanz. He’s found the explosives.

‘Good boy!’ Nanz shouts as he reaches toward his belt and pulls out Riggs’ paycheck: a toy. It’s an ellipsoid (a 3-D oval) made of the material used for tennis balls with holes on each end. Passing through the holes is a twisted rope. Nanz chose this toy because Riggs loves to play tug of war but also loves chewing on tennis balls.

The need for a bomb-sniffing dog

Riggs joined the Pitt police in December 2006. Pitt police chief Tim Delaney often tells the story of the event that prompted him to form the K-9 division. Before a Big East basketball game, someone found an unidentified school bag near the entrance of the Petersen Event Center. Pitt police officers sealed off the area and called the Pittsburgh bomb squad.

‘The days have gone by when you simply open a bag and see what’s inside,’ said Delaney. ‘That’s when it struck me. We need a bomb dog.’

As it turned out, the bag merely contained soda that a student had not been allowed to take into the game, said Delaney.

Although Riggs has never found any explosives in a real-life setting, he has been extremely active on Pitt’s campus and throughout the city of Pittsburgh since he joined the force. This past year, Nanz says he was used 94 times.

In the last year Riggs responded to five different bomb threats on Pitt’s campus. A person or persons threatened to set off bombs at the Cathedral of Learning on Sept. 27, Clapp and Langley halls on Sept. 28, Clapp and Langley halls again on Nov. 16, Chevron Hall on Nov. 9 and the Cathedral again on April 9, said Pitt police.

After the threats were received, the buildings were evacuated, students registered for the University’s Emergency Notification Service were notified via e-mail, voicemail or text message, and Riggs swept the buildings along with other local bomb-sniffing dogs.

In a phone interview on Aug. 1, Delaney only said that those cases ‘are under active investigation.

‘They focused on certain areas, so there are patterns that we are investigating,’ said Delaney.

Pitt police said the threats were called in to Allegheny Dispatch 911 or Pitt’s emergency line.

Riggs routinely sweeps Heinz field before every Pitt football game and the Petersen Event Center before men’s and women’s basketball games. He conducts sweeps before all special events that attract large crowds, such as commencement ceremonies, political rallies and concerts.

During the Democratic primaries and early parts of the presidential race, Riggs swept venues where presidential candidates spoke, including Sen. Barack Obama’s speech at the Petersen Event Center.

At this year’s commencement ceremony on April 27, Delaney said he called on Riggs and Nanz to handle a situation similar to the incident that first prompted him to form the K-9 unit. Someone sitting in a section reserved for guests, most of whom were family members of the graduates, informed a Pitt police officer about a suspicious school bag. People in the section said a young man had sat down, then walked away and left his bag on the seat. The officers asked surrounding attendees if they knew who this man was, and no one knew, said Delaney.

Police officers then asked the guests in the section to move to an adjacent section, while Riggs, who was already in the building, sniffed the bag. He found no explosives. When Riggs left the section, the guests who had moved to the next section began clapping, said Delaney.

‘That’s what struck me — that the parents clapped,’ said Delaney. ‘And he does this every day.’

The young man who owned the bag returned shortly thereafter. He was there to see a friend graduate and simply didn’t know anyone in the section, said Delaney.

Not quite like other dogs

At first glance Riggs seems to be no different from a typical Labrador: friendly, with boundless energy. The first time he entered Delaney’s office, he jumped straight for the commemorative baseballs on Delaney’s desk. But he’s not quite like other dogs.

‘Most dogs aren’t into explosives,’ said Delaney.

Riggs is smaller than any of the dogs he trains with at the airport. But size is irrelevant when it comes to finding explosives, said Nanz. What matters most, he said, is the dog’s work drive. Trainers look at how hard a dog is willing to work for his reward, which is typically a toy.

Riggs is 3 years old and ‘still has a lot of puppy in him,’ said Nanz. He lives in Nanz’s home, where he has his own room. Nanz said when Riggs is older he might let him roam the house freely, but at this point, he fears Riggs’ boundless energy could cause damage to the house.

Riggs eats two cups of Eukanuba dry dog food every morning and two cups at night. He is never allowed to eat table scraps. Nanz said he does not want Riggs to learn the scents of popular foods, because these scents could distract him from his job of smelling explosives.

‘When you’re searching something you don’t want him smelling a hamburger,’ said Nanz.

End of the day

In order to finish the luggage sweep, Nanz had to get Riggs’ beloved toy out of his mouth. He yanked the rope from Riggs’ clenched teeth.

‘Ar, ar, ar, ar!’ Riggs barks as he runs in circles around Nanz, who puts the toy back into a compartment on his belt.

Then, Riggs continued to sniff bags. He came to a small black suitcase and sat next to it.

‘Wooha, ha ha ha!’ Nanz shouted. ‘That’s my boy!’

There were explosive materials placed in two of the 35 suitcases, and Riggs identified both of them.

After the dogs finish that luggage sweep, a couple of officers rearranged the suitcases for the final sweep of the day, while the dogs waited in the cars.

When it’s his turn, Riggs trotted back into the building wagging his tail. This time, the bags are placed together and stacked in clusters throughout the room to simulate a natural airport setting.

Riggs located both bags in just a couple of minutes, and he’s finished.

Nanz took Riggs back to the car. On the way, Riggs stopped to relieve himself on a silver pole, where almost all of the dogs had already marked their territory.

When Nanz and Riggs get back into the car, Riggs lay on his stomach in his gated area and relaxed after a long day of work.