Last week, the third floor of the New Haven Police Department headquarters resounded with howls.

“Boris!” Officer Steve Silk grunted under his breath to his unyielding partner, a three-year-old German Shepherd.

In a graduation ceremony Friday, Boris and Silk became one of three dog and handler teams certified as members of the NHPD’s canine patrol unit, newly revived after two decades. The NHPD sees patrol dogs as a powerful tool for apprehending criminals, finding missing persons and detecting narcotics. Critics, such as community activist Barbara Fair, see the dogs as a polarizing wedge between the community and police.

For the past 20 years, when New Haven police officers needed to track a fleeing suspect or recover evidence from a crime, they have relied on neighboring police departments, meaning they had to wait while dogs from other departments were called, giving criminals time to get away, said Captain Leo Bombalicki, who will oversee the unit.

The operation started in Europe. Besides Xander, whom canine Officer Lars Vallin has owned since puppy-hood and donated to work on the unit, the two other dogs used in the canine unit are imported from the Czech Republic. Scribner said that historically, police departments have had easier time working with European dogs than with American ones, because there is a longer-standing tradition in Europe of breeding working dogs.

But quality does not come without a price tag: Batang and Boris, both German Shepherds, cost the NHPD $12,000 each to purchase, fly to America and train. This cost does not include the cost of the handlers’ salaries, or the special K-9 patrol cars purchased specifically to accommodate the dogs.

Once they arrived on American turf, the dogs were assigned to Reneé Forte and Silk, who were selected by the NHPD out of a 17-person applicant pool based on their police records and a panel interview.

Batang and Boris immediately moved into Forte and Silk’s houses, where they will continue to live for the length of their service. For a month before any sort of training, the handlers were instructed to bond with their dogs: Feed them, pet them, walk them and generally get to know them.

“The kids love him but don’t really play with him,” Silk said of Boris. “He’s a resource, not a family toy.”

Before they were certified to patrol the streets, New Haven’s dog and handler patrol teams endured eight weeks of intensive training.

One session of obedience training took the teams to the New Haven Green last Monday. Forte yelled at Batang in German, the language he has been trained in since birth. She directed Batang to stay as she put about 30 yards between them. A brave squirrel darted only feet in front of the dog’s powerful muzzle, but he remained decidedly where he was, crouched on the grass. Forte signaled for Batang to come, and he exploded forward, reaching her in mere seconds.

After obedience, it was on to narcotics training in a U-Haul parking lot a mile up Whalley Avenue. New Milford Police Sergeant Bill Scribner, a trainer who has helped to set up canine units for more than 30 police departments in Southwest Connecticut, placed drugs such as cocaine and heroin into metal boxes, which were hidden in strategic locations among five U-Haul trucks. Once the dogs sniffed out the boxes, they were rewarded with a toy. Even when the dogs start working real jobs on the streets, they will also be rewarded with toys.

Despite the potential gains of having trained police dogs, some New Haven activists are vehemently against the unit’s revival.

Forte recalls the story of Gary “Chris” Tyson, an 18-year-old West Haven resident who was killed in 2002. At the scene of a reported fistfight, police set a dog on Tyson, who was hit by a car while fleeing through Interstate 95.

“Many people are scared to death of dogs, myself being one of them,” Fair said. “Using police dogs projects an image [to the community] of them versus us.”

In response, New Haven Police Chief Frank Limon said there will more accountability and better dog training than there has been in the past — at a time when police are asking the community to help them curb a spike in gun violence, with 11 murders so far this year.

Bombalicki said he hopes that the dogs will be just as successful today as they were 20 years ago.

Back before the original canine unit was disbanded, Bombalicki was working undercover with his dog, Thor, when they spotted a suspicious-looking vehicle. As they approached it, a man with a handgun popped out. Thor scrambled out of the patrol car and lodged himself onto the hand of the assailant.

“Saved my life,” Bombalicki said. “I might not be here if it weren’t for Thor.”