The never-before-heard details of the Douglas Garland investigation from lead detective

• For the latest news, see: Douglas Garland sentencing to hear from victims' family members

With a two-week-old baby at home, homicide Det. Lee Treit was, as they say in his unit, "in the chute" on deck to lead the investigation into Calgary's next suspicious death.

Thatwas June 29, 2014, the last day Nathan O'Brien, 5, and his grandparents, Alvin and Kathy Liknes, were seen alive when the boy stayed for a sleepover, snuggled into the same bed as his grandmother.

When his mother arrived to pick him up the next day, Nathan and his grandparents were gone and there was blood all over the house.

Treitwas the officer in charge of the investigation, dubbed Operation Amber.

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One of the first things police did was issue an Amber Alert the longest-running in Alberta's history for Nathan.

Seasoned detectives held out hope for days that the missing family memberswould be found alive, despite the pools of blood found in the Liknes home.

But Operation Amber evolved into a mysterious triple homicide, even though the bodies of the the three family members were neverfound.

Douglas Garland, 57, who lived on a farm near Airdrie, Alta., was charged with three counts of first-degree murder about two weeks after the trio went missing. Jurors are now deliberating his fate.

'People had to be told to go home'

At Garland's five-week trial, some of the evidence gathered by investigators, including dozens ofexhibits, was laid out for the jury. About 1,400 pieces of evidence were gathered, although only 89 were presented in court.

Treit agreed to speak with CBC News about the Garland case in an effort to give credit to the hundreds of fellow officers involved in Operation Amber.

"I can't remember going home," Treit says of the time between June 30, 2014, when the family was discovered missing and July 14, when Garland was charged with murder.

During that time the detective's wife, who is also a police officer, would bring their newbornfor visits toCalgary Police Service headquarters where homicide detectives were essentially living working, eating and grabbing a couple hours sleep when possible.

"Two weeks of my life were one long day," Treit recalls.

The detective and his partner, Det. John Orr, weren't the only ones working almost round the clock and sleeping on chairs for a couple of hours at a time. It was all hands on deck with every detective fromboth teams of thehomicide unit involved in the investigation.

"It wasn't a matter of asking; around here you don't have to ask," says Treit."Everybody just puttheir lives on complete hold ... people had to be told to go home."

He estimates that 250 to 300 officers from every investigative department of the Calgary Police Service were involved.

"I never heard the word 'no,' not once," says Treit of his co-workers. "It was an incredible thing to be a part of."

6 persons of interest

Inthe hours and days after the family disappeared, Treit enlisted the help of the RCMP, the Canada Border Services Agency, Passport Canada, the Canadian Air Transport Security Authority, U.S. Homeland Security andMexican government officials.

Though he was not called as a witness at Garland's trial,Treittestified in December 2016 about the timeline, direction and scope of the investigation at a court hearing called avoirdire to determine the admissibility of certain evidence.

He testified that by the end of the first day of the investigation, investigators had compiled a list of six persons of interest. They included alocal sex offender, a man who had shot Alvin Liknes's daughter years before, a former house guest of the Likneses, two disgruntled formeremployees of AlvinLiknes, and Douglas Garland.

Investigators were assigned to interview each person and one by one they were all eliminated as possible suspects, except for Garland.

1,300 tips from public

Treit worked closely with his partner, Det. John Orr, and Det. Dave Sweet, who wasin charge of drafting search warrants that allowed officers access to the Garland farm and Liknes home.

In two weeks, police received nearly 1,300 tips from the public. Just days into the investigation, calls, tips and updates attached to the original case number caused the police department's computer system to crashand a second number had to be assigned.

Among the many tips received was one that the family had been spotted in Hinton, Alta., which was checked out by Det. Mike Cavilla who was in charge of following up on possible leads.

The investigators' hub, or control centre, was the homicide board room. Treitbarely left the room along withascribe who recorded everything from witness statements to resource requests and phone calls.

The early days were spent delving into the finances of the Likneses, canvassing neighbours, reviewing CCTV footage, and organizing press conferences;one for the O'Briens to make a public plea for the return of Nathan, and another for police to ask those who attended an estate sale the Likneses held on the day they disappeared to volunteer to be fingerprinted and tell police the items they'd purchased.

Above and beyond

Police were contacted on July 3, 2014, by CenovusEnergy, the company that employed Nathan's father, Rod O'Brien, which offered to finance a ransom if a request for money in return for the family members was made.

Had a ransom demand been made, Treit says Calgary Police Service policies on hostages would have kicked in, meaning the robbery unit and negotiators would get involved.

"We knew if that aspect reared its head ... we would have to give that part of the investigation over to those units," says Treit.

That same day, the RCMP offered to fast track any exhibits local police could get to the crime lab in Edmonton.

"They were giving us a turnaround time of three to five days which is virtually unheard of," says Treit. "So that was a priority."

Swabs taken from the bloodied Liknes home were driven to Edmonton where Treit says lab technicians were waiting at the door for Calgary officers.

"At the crime lab, the employees there had the door open when investigators arrived and they were going straight into the lab with these exhibits," he says.

Defence tries to have evidence tossed

In November and December 2016, defence lawyers Kim Ross and Jim Lutz fought to have evidence gathered from the Garland farm during and after awarrantless search, deemed inadmissible at their client's murder trial. But their request was denied.

On July 4, 2014, after police were pointed in Garland's direction by his sister and brother-in-lawTreitacted quickly, directing a search of the farm, even though police did not have a warrant, believingthe family members might still be alive. The law does allow for searches under"exigent circumstances."

But that search was only supposed to be in areas where Nathan, and the Likneses could be hidden. Police were not to look in smaller spaces until a warrant had been drafted.

OneRCMPofficer did look in adufflebag and found handcuffs, a large knife and abillyclub whichthe Crown would later refer to as Garland's "capture kit."

When officers arrived at the farm, a burn barrel was stillsmouldering and the hope of finding the family alive began to fade.

"Myself, in my heart, I had moved past the idea that we were looking for a live body on the farm," says Det. Sweet.

The investigation didn't end after Garland was behind bars. A Calgary police officer spent 10 months sifting through ashes found on the Garland farm looking for evidence.

When asked how he feels about his role as leader of the investigation, Treit is humble.

"I'm never going to take credit for this, not one iota. Itwas a completeand total team effort," he says.

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