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Male civilian victim ID'd as local musician Donnie Robichaud, 42

Police officers killed ID'd as Lawrence Robert Costello, 45, and Sara Burns, 43

Suspect is a 48-year-old Fredericton man who was arrested in an apartment in the 200 block of Brookside Drive. He is being treated in hospital

Dr. Everett Chalmers Regional Hospital treating multiple victims

Two police officers and a local musician were among the four people killed Friday morning when a gunman opened fire in a residential neighbourhood of Fredericton.

Bass player Donnie Robichaud, 42, has been identified by his cousin as the male civilian victim in the shooting that also claimed the lives of police officers Lawrence Robert Costello, 45, Sara Mae Helen Burns, 43, and a woman whose name has not been released.

Robichaud, a father of three, "was the best guy you could ever meet," his cousin and best friend Sean Callahan told CBC News.

He moved into the building where the shooting occurred just a few months ago.

Robichaud, 42, played bass guitar in several local bands. (Facebook)

Costello, a 20-year police veteran, is survived by his partner and four children. Burns joined the Fredericton Police Force in 2016 but had served as an auxiliary officer for two years. She leaves behind her husband and three children.

Our deepest condolences to the families of our fallen members 45-year-old Lawrence Robert Costello and 43-year-old Sara Mae Helen Burns and the other victims in this morning's shootings. <a href="https://t.co/9TeWn5OqWx">pic.twitter.com/9TeWn5OqWx</a> —@CityFredPolice

"In this dark time, I can say with certainty that the citizens of Fredericton were being exceptionally well served and that those that were killed this morning were taken very good care of," Leanne Fitch, chief of the Fredericton Police Force, said at an afternoon news conference.

Police survey the residential area of the shooting, which was on lockdown for several hours early Friday. (Keith Minchin/Canadian Press)

"I couldn't be prouder of the men and women that serve this city, and I want to reassure the public that we'll continue to do so in the coming days, months and years ahead."

The 48-year-old suspect, who has not yet been identified, is in hospital and is being treated for serious injuries.

The hospital said it was treating "multiple shooting victims," but police provided no details about them.

Burns, 43, leaves behind a husband and three children. Costello, 45, is survived by a partner and four children. (Facebook)

Fitch, Fredericton Mayor Mike O'Brien and New Brunswick Premier Brian Gallant all spoke at the news conference but shed little light on what happened.

"We are deeply saddened by the loss of our officers today," O'Brien said. "Our love and support goes out to everybody. In this community. We grieve together, but we'll heal together as well."

Watch the Fredericton police update on Friday's fatal shooting:

Fredericton police, the RCMP and city officials provide details of the fatal shooting in Fredericton's north end, which claimed the lives of four people, including two police officers. 20:11

Police said they responded to reports of gunfire at an apartment complex on the 200 block of Brookside Drive in the city's north end at 7:10 a.m. AT.

"Officers engaged with the suspect, and shots were fired by police," said Deputy Chief Martin Gaudet.

Fredericton police and RCMP officers survey the area where the shooting took place. (Keith Minchin/Canadian Press)

A perimeter was set up and the neighbourhood sealed off while residents were told to stay inside.

Gaudet said the police officers who died were the first on the scene. They saw a man and woman lying on the ground — the two civilians who were killed — and were shot as they approached.

At 9:30 a.m., police entered an apartment and arrested the suspect. A window on the top floor of the building showed holes left by tear gas canisters.

Police declared the threat to the neighbourhood over at about 11 a.m.

"Obviously, this is incredibly difficult for our officers and for our community," Gaudet said. "No one ever wants to lose a colleague or friend, especially in this kind of situation."

Gaudet said he couldn't provide any information about how many other people were wounded in the shooting or their conditions, as the investigation is ongoing.

Friday's shooting happened in a residential area in the Brookside Drive area on the north side of Fredericton. (CBC)

"The finer details of the call will be determined in the investigation," he said.

Ross White, the chief superintendent of the New Brunswick RCMP, said the major crimes division assisted local police in the investigation Friday. The Mounties will take over the homicide investigation.

RCMP issued a release Friday evening asking the public for photos and videos of the shooting to assist the investigation. A link was provided for files to be uploaded anonymously.

A witness describes harrowing moments of watching shots fired at his building:

A north Fredericton resident describes his terror at seeing shots fired toward his building, passing close to his son's bedroom. 2:09

Residents can't return home while investigation is ongoing

At least a dozen people displaced from the apartment complex where the shooting occurred will need Red Cross assistance.

The residents of the buildings were told they can't go back to their apartments until the investigation is completed.

On Friday evening, at least 20 people were gathered at Willie O'Ree Place, an arena, waiting to find out where they will spend the night. Joseph Cartwright, his partner and young child were among them.

A candlelight vigil was held Friday evening at St. John the Evangelist Anglican Church in Fredericton. (Andrew Vaughan/Canadian Press)

"The Red Cross took people up here so we were like, 'OK, they wouldn't let us get our cats, they wouldn't let us get our cars, our clothes, nothing.' They said something about putting us up. They're not sure yet where," he said.

A Red Cross volunteer said the organization will find hotel accommodations for people who can't stay with family or friends.

Early in the morning, eyewitnesses said they heard dozens of shots and soon saw police around the area where there is a cluster of apartment buildings.

Flowers and messages have been dropped off outside the police station in downtown Fredericton. (Julia Wright/CBC)

The neighbourhood was locked down and people were told to stay inside their homes. Police also told residents to avoid the Brookside Drive area, a major stretch of road that leads to the popular Brookside Mall.

'The bullets passed from the wall and go to my son's bed'

Parisa Motallebikia, who lived near the apartment where the shots were fired, said a man shouted at her and her husband when they were inside their apartment.

"Our windows broke, and the bullets passed from the wall and go to my son's bed. In front of my son's bed.

"And then we came out of [the] building, and again, we heard the shot."

Bullet holes riddle a window in an apartment building at the site of the shooting. (Andrew Vaughan/Canadian Press)

Shortly before 9 a.m., an apartment building at 237 Brookside Dr. was evacuated.

About two hours later, when police confirmed there was no further threat to the public, the lockdown was lifted.

At the time, police would only say they were investigating an "ongoing incident."

IMPORTANT: Please do not post information about the position or activities of police or first responders. <br><br>We are still working an active incident. We will release confirmed information as soon as we can. —@CityFredPolice

Federal Public Safety Minister Ralph Goodale said the investigation is in its early stages, so little is known.

"What we do know is that four Canadians are dead, and that is a huge tragedy for the whole country," Goodale told reporters in Sarnia, Ont., where he was announcing the name of a new federal building.

Public Safety Minister Ralph Goodale talks about the Fredericton shooting 0:30

Sgt. J. P. MacDougall, district commander of the West District RCMP, asked reporters at the scene to pass any pertinent information to investigators as they were interviewing witnesses.

"We just don't know what we don't know at this point," MacDougall said. "We're at the early stages of a very significant event."

Hospital treating multiple victims

Christopher Gill woke up to a number of police officers and the sound of gunshots outside his apartment at 237 Brookside.

"I looked out the window, and there were three police cars on the street just across from where I live," he said. "I saw one cop just standing against the building … like he was waiting for somebody to come out."

A resident describes waking up to gunshots:

A witness describes being awoken by gunshots near his home in Fredericton 8:46

On Twitter, Horizon Health Network, one of two health authorities in the province, said the Dr. Everett Chalmers Regional Hospital was treating multiple shooting victims.

Residents across the city have also been lining up outside the Fredericton hospital to show their support.

Dozens of residents lined up outside the Dr. Everett Chalmers Regional Hospital in Fredericton to show their support. (Joe McDonald/CBC)

Gallant, who was elected premier just four months after three Mounties were slain and two others badly injured in Moncton in June 2014, said officials in Fredericton have been doing "a great job in a very difficult situation" while ensuring the public's safety.

"Any type of event like this is just horrendous and very difficult to be a part of as a first responder," he said. "Imagine that you know or you assume that some of your colleagues have fallen during the incident."

The premier said Fredericton police did everything they could to keep people informed about the shooting and that government will offer support any way it can.

Watch Premier Brian Gallant's interview with CBC News Network:

New Brunswick Premier Brian Gallant praised the reaction of first responders and city officials to Friday's shooting in Fredericton, which claimed the lives of four people, including two police officers. 10:36

"It's so difficult for New Brunswickers," he said. "You can't make sense of something so tragic like this.

"The loss of life that we saw today did not have to happen, and that's why I think it's so difficult for the community, that's why we have to be there for one another over the next few days and weeks.

"I know all Canadians are behind the city of Fredericton, the victims, their families and our province as a whole … knowing that we have the big family that is Canada behind us will help us over the next few days. "

At this time, I would ask New Brunswickers, particularly those in areas identified by police, to keep informed about the situation as it develops and follow the instructions of law enforcement officials working in the area. —@BrianGallantNB

Fredericton Mayor Mike O'Brien tweeted Friday morning, "Our hearts are broken by the murder of our two brave police officers, let us all protect their families. "

In a statement, the mayor and council extended their sincerest condolences to Fitch, officers with the city's police force and everyone affected.

"The next few days will be a challenging time for our community as we deal with a loss that will no doubt be felt by many," the statement said.

Our hearts are broken by the murder of our two brave police officers. In this time of shock and grief, let us all protect their families. —@mikeobrien_fton

The president of the Canadian Police Association, Tom Stamatakis, said it will be especially difficult for the city's officers to return to work.

"The city needs to be policed and will need to be policed in the days and weeks following the shooting. How will officers go back to work tomorrow?," he told CBC Radio's As It Happens.

A canine unit was part of the police team that attended the shooting scene. (Keith Minchin/Canadian Press)

"It will be tough. You know, in the aftermath of an incident like this, there are going to be lots of emotions. People are going to be devastated. There will be relationships that will no doubt be affected.

"People will feel like, you know, they could have done more to help her or something could have been done differently. That's only natural in the aftermath of something like this."

Bullet holes and tear gas-entry holes were visible in this apartment building following the shooting. (Courtesy of Brett Gibbons)

A prayer vigil was held Friday evening at St. John the Evangelist Anglican Church on the city's north side.

The Anglican Diocese of Fredericton organized the vigil.

"Sometimes, all we can do is stand together in the darkness," said Bishop David Edwards of the Anglican Diocese of Fredericton, which organized the vigil.

Prime Minister Justin Trudeau and Goodale tweeted messages of support earlier Friday:

Awful news coming out of Fredericton. My heart goes out to everyone affected by this morning’s shooting. We’re following the situation closely. —@JustinTrudeau

All of Canada stands with the two brave Fredericton Police officers who lost their lives protecting their community today. Their families, friends and loved ones have our deepest condolences. —@RalphGoodale

Several police forces across the country also sent messages of solidarity and messages of support, and flowers and cards have been piling up outside the police station in Fredericton.

We at <a href="https://twitter.com/HfxRegPolice?ref_src=twsrc%5Etfw">@HfxRegPolice</a> are following the situation in Fredericton this morning. I have spoken to Chief Fitch personally to offer her any support we can give. We stand with <a href="https://twitter.com/CityFredPolice?ref_src=twsrc%5Etfw">@CityFredPolice</a> while they deal with this situation. —@JMBlais1

A witness tells CBC News he took cover when he heard shots outside his window: