Calgary police expanded search efforts for a missing 11-year-old boy to the entire city on Friday afternoon, asking members of the public to search their property.

On Thursday, Calgary police asked northwest Calgary residents, particularly in and around the Cambrian Heights neighbourhood, for help searching for the missing boy, named Parker.

Police expanded the search area to more neighbourhoods on Friday morning, before later asking the entire city to search for the boy.

Calgary police acting Staff Sgt. Scott Guterson asked the public on Friday afternoon to check their yards, garages, open vehicles, RVs, sheds, pools or anywhere else a child could go.

“It is unusual that he has not been found yet, which is again why we are asking for that community help,” Guterson said.

Calgary police will share an update on the search for Parker at a 4 p.m. press conference Saturday.

Guterson advised the public that if they come across Parker, they should not engage him, but instead call police. He said they believe the boy is non-verbal, and gets agitated when strangers approach him.

He was last seen shirtless, wearing grey shorts, black Skechers shoes and black noise-cancelling headphones.

He’s four feet 11 inches tall and weighs approximately 90 pounds, with brown hair and brown eyes. Guterson said Parker is autistic and functions at a two- or three-year-old level.

An emergency alert was broadcast on Saturday afternoon for Parker. Although police previously said the case did not meet the threshold for an Amber Alert, as foul play is not suspected, Calgary police said the provincial government made an exception in this case.

Family issues statement

In a statement Parker’s family said they have been living “every parent’s worst nightmare” since he went missing.

“Every hour that passes without knowing where he is or whether he is safe has been incredibly difficult for us,” the family said in its statement, sent out by the Calgary Police Service on behalf of the family shortly after Saturday afternoon’s emergency alert.

The family implored people to continue searching their properties for Parker.

“Parker experiences the world in his own way. He may not respond when his name is called, and he can become frightened when approached by people he does not know,” the family said.

“Parker is deeply loved, and he is missed immensely. We just want our son home.”

After Parker was seen Thursday at his day home in the 0 to 100 block of Connaught Drive N.W. between 11:08 and 11:41 a.m., the boy was last seen in the Thorncliffe neighbourhood between 12:30 and 1 p.m. on Thursday, Guterson said.

On Saturday, police released a CCTV photo of the boy captured during that time period Thursday on the 5000-6000 block of Travis Crescent N.E., in hopes it might aid in the search.

Police said Saturday investigators have received and assessed about 30 tips from the public and are reviewing some 50 hours of CCTV, security camera and dashcam footage. Anyone with additional footage is asked to contact police.

Clothing that’s believed to belong to Parker was found at noon Thursday in the 0 to 100 block of Northmount Drive N.W., police said.

Calgary police told the public they may see search teams, including an air support unit, mounted patrol team, mountain bike unit, canine unit and ground search teams, in the area.

“Essentially any available resource that CPS has, we have devoted them to this search,” said Guterson.

Guterson said police know the boy likes water and part of their search has been to check whether he’s near bodies of water.

Premier Danielle Smith implored Calgarians to assist in the search for Parker in a post on social media Saturday. She added the province has provided 74 search and rescue personnel to help local efforts.

Police are asking anyone with information about Parker’s location, or who may have CCTV or dashcam footage, to call 403-266-1234 or reach the police’s evidence submission portal.

Situations like this warrant emergency alert, advocate says

For Calgary mom Stephanie Karas, Saturday afternoon’s emergency alert came far too late.

“We’ve gotten alerts for tornadoes that have not touched down. We’ve gotten alerts for less, so I don’t know why there wasn’t,” she said.

Karas, a mother of two children with autism, says she’s lobbying the municipal and provincial governments to create an emergency alert protocol specifically for situations like this.

“Why isn’t there something for vulnerable youth and adults that aren’t equipped?” Karas said.

“It’s long overdue, so somebody’s got to start it,” she said. “And if the people of Calgary have to start it and are motivated behind Parker, then that’s what we’ll do.”

CBC News has reached out to the Alberta government for comment.