Rochelle Lall, 3½, was one of five people found dead in a Calgary home on Wednesday. (CBC)

Investigators are calling the deaths of five people in a northwest Calgary home a "domestic homicide," and on Thursday identified the man found among the dead as the likely killer.

"The events are looking towards the male in the house," Calgary police Chief Rick Hanson told CBC News, a day after police found the bodies of a couple in their 30s, their two daughters and a female tenant inside a home in the Dalhousie neighbourhood.

But, he added, "There's always the question of doing things absolutely thoroughly, absolutely 100 per cent correctly. You don't want to start an investigation that leads you down one road and then find out perhaps you should have been looking at something else."

At a police news conference later Thursday, Calgary police Insp. Guy Slater said while he stands behind Hanson's comments that the father is a suspect, he said it is not the only option police are considering. Slater said it would be a "disservice" to state categorically that the man was responsible at this stage of the investigation.

Kristen Lall, 5½, was one of five people found dead in a Calgary home on Wednesday. (CBC)

"The chief's comments still stand. Obviously, the preliminary indicators from yesterday's investigation have led us down that path and we continue to pursue that as one of many possibilities," Slater said.

Police rushed to a house on Dalhart Hill on Wednesday morning where they found the dead bodies as well as a one-year-old girl crying in her crib unharmed. The child was in the care of social services on Thursday, but officials said a family member was expected to pick her up later in the day.

Investigators were still combing "meticulously" through the evidence Thursday, Hanson said.

"At this point in time, there's a whole lot of work that's got to be done in regard to the background. You know, what happened that precipitated this," he said, adding investigators would also be looking at mental illness as a cause.

Police were withholding names of the dead, but friends and neighbours told CBC News they are Josh Lall, 34, his wife, Alison, 35, and their daughters Kristen, 5½, and Rochelle, 3½. The tenant has been identified as Amber Bowerman.

Josh and Alison Lall, seen on their wedding day, were said to be kind and devoted. (CBC)

Hanson would not confirm the identities, saying the medical examiner's office must provide positive identification.

Police are calling the deaths a "domestic homicide." Hanson said that description means "any violence between co-habitating couples."

Crew receive trauma counselling

Police and emergency crews were stunned by the horrific scene inside the Lall house, so much so that they are receiving trauma counselling.

"When it involves kids, it adds an extra dimension … they ought not to be victims, they ought not to be victims at such an early age," Hanson said.

The bodies have been removed from the home and police are hoping for autopsy results later this week, Hanson said. The cause of the deaths has still not been released.

"The investigators will start piecing together the events leading up to this … there are a lot of unanswered questions," he said. "Our investigators are being meticulously thorough on this one. We want to get the answers as much as people in the community want to know the answers."

Investigators would be looking into whether there was "a warning of some sort" that could have prevented this from happening," he said.

Father had taken the day off

On the day the bodies were found, Josh Lall had taken a "planned absence" from the architecture firm Cohos Evamy, where he worked, his boss told the Canadian Press.

Rob Adamson, chair at Cohos Evamy, said he was shocked to learn of the deaths, describing Lall as "kind-hearted."

He said there were no alarm bells raised when Lall didn't show up for work on Wednesday because the employee had arranged to have the day off.

Adamson said Lall had worked at the architecture design company for the last five years, starting as an intern.

"He is a person of strong character. He's hard-working. He's polite, friendly, respectful. He was a solid member of our team," he said, adding that his work was exemplary.

"There were no indicators to us at work of any problems. He was just a solid, come-to-work and get-it-done kind of guy."

Loving family, friends say

By Thursday morning, people had started placing flowers and children's toys on the front lawn of the Lall home, remembering a family that friends and neighbours described as loving and devoted.

Jennifer Klein saw details about the deaths on a news website Wednesday and recognized the home of her best friend, Alison Lall. She screamed and called her friend, hoping to hear she was OK, but there was no answer.

"I called her answering machine and I heard her voice," she told CBC News. "You can just tell she speaks with a smile, and you can hear it on the answering machine."

She and Lall attended McMaster University in Hamilton, Ont., where they studied occupational therapy and then both moved west at roughly the same time.

Klein said Lall was kind and didn't have any enemies, while Lall's husband, was loving, gentle and devoted.

"She waited for the right guy, and this is her first true love," Klein said of Lall.

Neighbour and friend Jerry Hauge described the family as "nice — they were just warm, open, smiling, caring people."

Hauge said the situation was "very tough, very emotional" for him.

"Knowing the family, we cannot believe that any of them could have done this to each other. There was just no indication of any kind of anger or unrest or anything like that," he said.

With files from the Canadian Press