CALGARY -- Police say a violent encounter preceded the disappearance of a couple and their five-year-old grandson.
Survivors of the confrontation that occurred last Sunday night or early Monday would be in dire physical shape, homicide unit Staff Sgt. Doug Andrus said.
"We can now confirm a violent crime occurred in that residence," Andrus said of the home of Kathy and Alvin Liknes.
"I would say somebody would be in medical distress."
Five-year-old Nathan O'Brien was on a sleep over at the home when the three vanished.
Andrus wouldn't say blood was found in the home, but said forensic investigators are working to determine who might have suffered injuries there.
Results from those tests could take a few days or weeks, the officer said.
Although there were no signs of forced entry, police said there was evidence someone was dragged from the home.
After speaking of progress in the investigation Friday, Andrus said he doesn't expect to issue updates over the weekend.
Earlier in the day, police released two photos captured by a surveillance camera of a green late 1980s, early 1990s Ford 150 pickup truck seen driving a few times around the area at the crucial time.
Authorities want to speak to the driver of the vehicle, which appears to be in good condition.
"The fact it was the night of the incident and it was driven in the area several times, it's a good possibility the people in the truck would have information," said Andrus.
Police äč who have more than 40 officers working on the case äč say they have no firm motives but have a number of theories as to why the crime occurred.
They say it might be related to an estate sale the Liknes' held at their home last weekend.
On Thursday, 75 witnesses who attended the sale spoke with investigators who say they're trying to determine what was purchased at the home and what might have been stolen.
"The list is incomplete because we haven't met with everyone who was at the sale," said Andrus, noting about 200 people were believed to have attended the two-day event.
"It's a very complex investigation äč we have a lot of unanswered questions."
He said police still retain optimism O'Brien and Alvin, 66 and 53-year-old Kathy Liknes will be found alive.
On Thursday, Andrus conceded it's odd no contact has been made by would-be kidnappers.
Meanwhile, a website, nathankathyalvin.com, set up to garner support for the beleaguered family continued to be swamped by well-wishers.
Entries on the site numbered more than 16,000 by 11 a.m. Friday, when it apparently crashed due to the weight of traffic.
One message, from a woman named Jenna, pleaded for the perpetrators to reverse course and release their captives.
"From my heart to yours I beg and urge you to make a decision today to take a step, any step, even a small step to help bring this situation to a close," she wrote.