The five officers stood in a semicircle in the fourth-floor exercise room at police headquarters.
They were waiting to be weighed; waiting to start a tryout that would stretch over the next 10 hours and demand immense physical and mental strength. The day-long contest is the first step in determining who will be the department's newest canine officer.
"This is probably going to be the toughest tryout you'll have in this department," canine trainer Chris Ladd, a 22-year veteran on the force, told the young men in front of him.
That was true in more ways than one Thursday.
The officers vying for the spot on the canine team are seeking to join a tight-knit unit of 11 other officers and their dogs. Until a year ago, there was a 12th member on the squad - Officer Jeffrey Yaslowitz, who was killed along with Sgt. Thomas Baitinger on Jan. 24, 2011, while trying to arrest a fugitive hiding in an attic.
Yaslowitz's spot has been vacant for the past year. But this week, days after memorial services marked the anniversary of the deaths, the department started the process of filling the post.
At the gym, the officers were evaluated on physical strength and flexibility. At the police training facility, near Boyd Hill Nature Preserve, the tests got harder.
One by one, the officers had to squeeze through an 18-inch pipe. They had to carry a 70-pound bag of dog food around a large field. They had to show off their handling skills with both trained and untrained dogs. With a padded sleeve, they were bitten by an 85-pound, long-haired German shepherd named Zeus. They were rushed and taken down by honey-colored Belgian Malinoises named Tomy and Timon.
Darkness didn't slow them.
As the sun set, the candidates marched into nearby woods. They crawled through swamps. They climbed up and over and down hills. They swam in Lake Maggiore, dogs by their side.
"If their dog were to go into a pipe, obviously the handler has to go through, too. If something were to happen to their dog, they would have to carry it," said Sgt. Dave Barr, who is in charge of the unit. "You spend more time with your dog than your family."
The five officers who tried out Thursday come from different divisions. Officers Jonathan Vazquez and Kevin Vater are part of the department's street crimes unit; Officer Tim Bley is a patrolman; Officer Thomas Qualey is a field training officer. A fifth officer works undercover and could not be identified.
Their motivations for trying out, however, were the same.
"It's always been a dream," said Bley, 28, who joined the force in 2010, a few months before Yaslowitz's death.
Thursday was the first time Bley had ever tried out for canine duty. The other four have participated in past tryouts.
The hardest part, they said, isn't the physical obstacles. It's the mental endurance needed to make it through the day.
"It means a little bit more this time," said Qualey, 27. "There's something else there, making you want to push harder, knowing why the spot is open."
The tryout was just the beginning of the process.
Each officer is evaluated not only by Barr and other superiors, but by existing canine officers, too. In fact, most of the all-male team watched and helped with tryout drills Thursday. (There have been female canine officers in the past, but none tried out this time.)
Then there are home visits.
Barr and others interview the officers' families and make sure the officers have enough space and a yard for the dog. They even talk to neighbors.
Officials hope to make their decision within the next few weeks, Barr said. After that, the selected officer and his new dog will go through a 16-week training course.
It won't be easy.
"We know there's a void in the squad," said Vazquez, 28. "There's no way you're going to fill the shoes he left. He'll be with us forever."