FREDERICTON -- A man charged with multiple murders at a Fredericton apartment complex is being described as seemingly "polite and pleasant," with police yet unable to offer the public any alleged motive for Friday's burst of violence.

Matthew Vincent Raymond, 48, of Fredericton is accused of killing 32-year-old Bobbie Lee Wright, her boyfriend Donnie Robichaud, and police constables Robb Costello and Sara Burns, police said Saturday.

Raymond has lived in the complex for about four months, said Judith Aguilar, an office manager for Sunfield Apartment Rentals, the complex's owners. Aguilar said he is an avid cyclist who often came into pay his rent in cash while wearing a bike helmet.

"He seemed like a reasonably normal person. He seemed normal and made small talk every time you saw him," Aguilar said Saturday. "He came in every month to pay rent. He was always polite and pleasant."

Both Robichaud, 42, and Raymond were residents of the complex, but lived in different buildings, she said.

Investigators have not established a relationship between the accused and the deceased, said Fredericton deputy police chief Martin Gaudet.

"That is a piece of information we're looking to establish, and we haven't established it yet," he said at a news conference outside police headquarters, where residents have placed flowers, notes and teddy bears for the fallen officers.

While little is known about the alleged gunman's potential motives, police have begun piecing together what happened.

Investigators allege a man shot at Wright and Robichaud from an elevated position shortly after 7 a.m. Friday, using a long gun. They said Costello and Burns were responding to the shooting and found two victims on the ground, a man and woman. That's when the officers were shot, police said.

Officials said Saturday that just one person was hospitalized after the shooting -- Raymond, who is being treated for serious injuries after being shot by police.

He is to remain in custody until he appears in court Aug. 27, police said.

In an interview, Aguilar said that at one point maintenance workers needed to do some repairs in his apartment and he didn't want them there while he wasn't present.

"He seemed concerned, he said he had an expensive computer and an expensive bike and he didn't want anyone to be there alone," she said. "They didn't even have to go all the way into the apartment, they were just fixing his door frame at the time."

She said she didn't interact with Robichaud much because he didn't come into the office to make his rent payments, and she did not know if he knew Raymond.

As of Saturday morning, the area surrounding the crime scene remained cordoned off by yellow tape, but police allowed some shaken residents through to check on their pets.

An RCMP forensic unit was on scene and police could be seen moving through the complex of low-rise brick apartments.

More than half a dozen bullet holes could be seen in the window of an upper-floor corner apartment, while a second window appeared to have been mostly smashed.

Joe Cartwright emerged from the building to say all the doors in the complex had been kicked in and one of his cats had escaped.

Cartwright said his girlfriend, Caitlyn Francis, and four-year-old son had been at home during the shooting, and he rushed to the scene in a panic once he realized his family could be in danger.

"I'm very torn up," he said. "I'm not doing very well at all, my girlfriend's not, my son's not, so we're going to go and just try to calm down from this."

Francis said she had been getting her stepson ready for daycare at 7:10 a.m. when she heard police sirens.

She looked out and saw a police car pull in, driven by a man she believes was Costello.

"Not even a minute or two later I heard the first gunshot," she said Saturday morning, as she stood wrapped in a Red Cross blanket outside the apartment complex.

"I started bolting into my apartment and heard a second one."

The next moments were a blur as she focused on keeping her stepson safe and calm as several more shots could be heard, she said.

"I pulled him into my bedroom, got him to lay on the floor back there, tried to play cartoons for him, but he still could hear (the gunshots)," she said.

"There was no playing off what those sounds were, he knew it."

Five minutes after the gunfire ceased, she said she peeked out the window and saw the leg of a person who was lying on the ground.

Police have asked anyone who captured photos or video of the incident to come forward.

Fredericton police said Friday night that the city and Red Cross had found lodging for 50 residents unable to return to their homes on Brookside Drive on the city's north side.

At least 10 children lost a parent in the shooting.

Costello, 45, was a 20-year police veteran with four children, while Burns, 43, had been an officer for two years and was married with three children.

On Saturday evening, the Fredericton police released statements from both officers' families.

Burns' family expressed sympathy for the families of Costello and the other victims, and asked for privacy as they grieved.

"Sara absolutely loved her job, and went to work each shift committed to serving this great community. We appreciate all of the thoughts and prayers during this difficult time," the statement said.

Costello's partner, Jackie McLean, said in a statement of behalf of the family that she also sought privacy, but wanted to say a few things about him.

"Robb was the single most positive person I have ever met; and that was obvious to everyone who met him. He had a special way of dealing with people -- fair, but strong and tough when needed. He was the only officer I've ever known to write a ticket and have the recipient thank him for it," she said.

"He was often heard to say he was a 'CFL' -- constable for life. He loved the people, he loved the variety of calls, but mostly he loved being able to de-escalate an escalating situation. I know he responded eagerly and willingly to that last call."

Robichaud, a father of three who played bass and sang in a few local bands, had just begun dating Wright.

"It is just unfair, cruel and senseless. I have a lot of mixed emotions right now. I just pray to God that justice is served in this situation," said Amanda Lee Leighton, 32, of Fredericton, a close friend of Wright.

"I feel horrible that this could happen to one of the nicest girls I had ever known. Literally, she never fought with anyone or disliked anyone," she wrote in a text.

-- With Nicole Thompson and Gabriele Roy in Toronto and Alex Cooke and Michael Tutton in Halifax