Photo: The Canadian Press

Hundreds of mourners lined up in downtown Fredericton on Thursday for an emotional public visitation for two city police constables killed in the line of duty.

Constables Robb Costello and Sara Burns were gunned down at an apartment complex on Fredericton's north side Friday, in a shooting that also claimed the lives of civilians Bobbie Lee Wright and Donnie Robichaud.

Inside a dimly-lit ballroom at the Fredericton Convention Centre, the families of Costello and Burns stood near large framed photographs of the fallen officers as a steady stream of visitors paid their respects to the grieving families.

Two large projectors on either side of the room played slide shows with pictures of the officers at different stages of their lives, from what appeared to be a high school graduation and prom night to cradling a newborn baby and apple-picking.

Many people left the solemn ceremony in tears, struggling to cope with the aftermath of the violent shooting that has gripped the community for the last week.

"There's some young families up there that lost a loved one," said Supt. Sheldon Currie with Corrections New Brunswick.

"It's really important to be here today to support the families. We're all one big family and we're always here for each other."

Sophie-Anne Lalonde, an elementary teacher in Fredericton, said she taught French immersion to Burns' youngest son.

"It's definitely tough knowing that he's going through that — that all of the children have lost a parent. It's devastating," she said.

The Burns family issued a public statement Wednesday saying "we have heard one common theme since the passing of Sara and Robb."

Burns' husband, Steven Burns, said people have repeatedly told the family, "They were two of the most positive people anyone had ever met."

An obituary said the 43-year-old Burns fulfilled her lifelong dream of becoming a police officer three years ago, after more than 14 years as a stay-at-home mom of three boys.

"Not a day would go by when she didn't say aloud, for everyone to hear, 'I love my job,'" the obituary published on the McAdam's Funeral Home and Crematorium website said.

Steven Burns said his wife could "brighten a room with her smile in an instant, and make anyone feel at ease seconds later with just a few words.

"Sara was put on this Earth to help people and everything she has ever done in life was to help people," Burns said. "We are so proud of the person and human being that she was, and we will miss her dearly."

An obituary for Costello said he loved being a police officer, and though he spent time in specialized units, he eagerly went back to patrol, which the obituary published on the Bishop's Funeral Home website called "his true love.

"He was away at the police academy while his first daughter (Kassie) was an infant," the obituary said.

"He joined the Fredericton Police Force immediately after finishing the academy. His daughter Kaitlyn was born in Fredericton, and Robb had a strong connection to the city he served."

Costello was "so proud of both his girls and the women they were becoming," the obituary said.

"To his step-children he was known as 'Faux Pa,' and he loved them like they were his own."

On Saturday, thousands of police officers and first responders from across the country are expected to attend a regimental funeral for the two officers.