Calgary Police Chief Rick Hanson says first and second degree murder charges are being filed in connection with the disappearance of Nathan O'Brien and his grandparents at a news conference in Calgary, Alta., Monday, July 14, 2014.

Image Credit: THE CANADIAN PRESS/Jeff McIntosh

CALGARY - A relative of a missing Calgary boy and his grandparents says the family won't believe the three were murdered until their bodies are found.

In an email to The Canadian Press, Teena Prevost, the sister-in-law of Kathryn Liknes, says her family is holding out hope they're alive.

Police have said first and second-degree murder charges are pending against a man arrested earlier today north of Calgary.

Murder charges are pending in the mysterious case of a missing Calgary boy and his grandparents with police saying there's strong evidence to suggest they're dead even though their bodies have not been found.

Calgary police Chief Rick Hanson told reporters a man was arrested early Monday, but couldn't be identified until he appeared before a justice of the peace on the charges later in the day or early Tuesday.

The man is to face two counts of first-degree murder in the deaths of Alvin and Kathy Liknes. One charge of second-degree murder is to be laid in the death of five-year-old Nathan O'Brien.

Hanson said the arrested man is from Airdrie, a community north of Calgary, but would not confirm media reports that it is Douglas Garland. The 54-year-old lives on an Airdrie acreage with his parents and was earlier questioned as a person of interest in the case.

Hanson would only say police are not looking for any other suspects.

The missing family members were last seen two weeks ago, on June 29. The couple had held an estate sale at their home that weekend and their grandson stayed for a sleepover.

When his mother went to pick him up the next day, no one was home.

Police had said there was evidence something violent had happened in the grandparents' house, but had always held out hope the three would be found alive.

Shortly after the three disappeared, Nathan's parents issued a tearful plea through the media asking for their return and urging their "superhero" son to be brave.

"Even as the days went by there's always a hope, there's always a glimmer of hope," Hanson said. "Unfortunately with the laying of the charges, we've taken that hope away from the family. So they are devastated."

While refusing to discuss the evidence in any detail, Hanson said there is no "smoking gun" that finally led to the arrest.

Investigators met with Crown prosecutors on Sunday to go over evidence that had been gathered over the two weeks, he said. They determined charges were warranted. An Amber Alert issued shortly after the family members were reported missing was also cancelled.

"It was clear at that point that this was no longer a missing persons investigation. This was a homicide investigation," Hanson said.

From the beginning, the case captivated people across the country. Thousands of people wrote messages on a blog for the family and police received more than 900 tips from the public, including sightings reported from coast to coast.

Despite the charges, the police chief said the case is not closed and investigators will continue to search for bodies of little Nathan and his grandparents.

Hanson renewed calls for rural property owners to search their land for anything out of the ordinary.

Garland was first questioned more than a week ago, then held on unrelated identity theft charges. He was released from custody on Friday. His lawyer on those charges, Kim Ross, did not return messages seeking comment Monday.

Investigators have been searching his parents acreage northeast of Airdrie, including several fields and sloughs on and around the property.

Garland has ties to the Liknes family. His sister is in a relationship with a member of the Liknes family.

Police earlier said they were looking into whether there was a business connection to the missing persons file.

Alvin Liknes was involved in several oil and gas companies, including Winter Petroleum Ltd., which media reports say was forced to close a few weeks ago. The CBC has quoted a police source as saying Garland and Alvin Liknes had a dispute over a patent for a gas device.

Court documents show Garland has a criminal record and mental issues.

In 2000, he was sentenced to 39 months for making amphetamines at his parents' farm. Before he went to prison, he jumped bail and lived for several years in Vancouver using the identity of a dead person.

The Parole Board of Canada gave him accelerated release after six months, noting in its decision that Garland's prior criminal record consisted of various property offences over the course of 20 years.

His mental health played a role in the crimes, the board said, but a psychologist determined that Garland had "little violence potential to others.'' It ordered a psychologist and psychiatrist to closely monitor him during his release.

After news of the arrest, Prime Minister Stephen Harper sent out condolences on Twitter: "Our thoughts and prayers are with the O'Brien and Liknes families during this time."

Calgary Mayor Naheed Nenshi also released a statement: "I, like all Calgarians, am terribly saddened to learn about the murder charges that were laid today related to the missing persons investigation in our community. My heart goes out to the Liknes and O'Brien families, and I know that they will continue to have the support they need from all of us at this very difficult time."

The Canadian Press

TIMELINE OF EVENTS IN THE CASE OF THE MISSING 5-YEAR-OLD AND HIS GRANDPARENTS

June 30: Calgary police issue an Amber Alert after five-year-old Nathan O'Brien and his grandparents, Alvin and Kathryn Liknes, are reported missing. Police say Nathan's mother had dropped her son off at the Liknes home the night before for a sleepover. She found all three family members missing when she went to collect him the next day. Police describe all three disappearances as "suspicious."

July 1: Police express interest in speaking to anyone who attended an estate sale at the Liknes home in the weekend leading up to the disappearances.

July 2: Nathan's parents, Rod and Jennifer O'Brien, issue a nationally televised plea for their son's safe return.

July 3: Police say footage from nearby closed-circuit televisions as well as tips from the public have moved the investigation along, but decline to provide details.

July 4: Police confirm that a violent incident took place at the Liknes home, adding they recovered forensic evidence. They also release images of a green Ford pickup truck and say they believed the unidentified driver may have some information.

July 5: Calgary police and RCMP descend on a property near Airdrie, Alta., just north of Calgary. Police recover the green Ford and take in Douglas Garland for questioning.

July 6: Police enlist the help of a dog and a boat as they continue to comb the Airdrie property. Garland is released, but still publicly declared a person of interest.

July 7: Douglas Garland, 54, appears in a Calgary court on an identity theft charge unrelated to the Liknes/O'Brien disappearance. He is held in police custody pending a bail review. Rod O'Brien tells reporters at the courthouse that there is a connection between Garland and the family, but would not elaborate.

July 8: Calgary police say they have other leads to explore besides Garland and the Airdrie property, but offer no details.

July 9: Police say they've expanded their search to the Spyhill Landfill northwest of Calgary. They also confirm that Garland's sister is in a relationship with a member of the Liknes family, and that the Airdrie property belongs to his parents.

July 10: Police say they are probing business dealings in the Liknes family as part of their investigation. Officers did not provide details, but reports surfaced that Alvin Liknes recently had to close his gas exploration company after equipment was seized for unpaid taxes. Police said they had also begun searching other city landfills. Later that day, about 500 people attended a candlelight vigil at a community centre near the Liknes home.

July 11: Garland is released from police custody on bail and given strict conditions, including instructions not to return to his parents' Airdrie farm where police were still conducting searches.

July 12: Police return to the Liknes home to conduct more searches even as they continue to sweep the Airdrie property and local landfills.

July 13: Police conclude searching the Liknes home but say the investigation continues at the Airdrie property and local landfills.

July 14: Calgary police say two charges of first-degree murder and one charge of second-degree murder are pending in the case. Police won't immediately identify the suspect because charges had not been laid.

News from © The Canadian Press, 2014