It was the Saturday morning of an August long weekend when three-year-old Casey Bohun vanished from her quiet suburban home in North Delta, B.C., sparking a decades-long mystery that remains unsolved today.

Monday marks the 30th anniversary of Casey's disappearance. Despite the time that has passed, Insp. Guy Leeson with Delta police says officers still investigate the one or two tips a year that still come in.

"It's a cold case but all these types of missing persons investigations remain open," Leeson said. "If anybody knows anything in relation to Casey's disappearance, we'd like them to come forward."

Casey was a red-haired child with a chip in her left front tooth at the time.

Delta Police Department

Over the years, some of the tips have even come from people who thought they may be Casey, but Leeson says DNA never matched anyone to the missing girl.

Crystal Dunahee knows what it means to not give up hope that someone has pertinent information that could provide answers.

Dunahee's son, toddler Michael Dunahee, disappeared from a playground in Victoria just a couple of years after Casey did. The family still encourages people to come forward with information, and generates tips from events like an annual walk they organize.

"It's going to be that one tip that brings a conclusion to our ongoing misery," Dunahee said.

These types of tragedies are often hard on families, Dunahee says. The Bohuns were no different. Sister Stacy Bohun was later placed in foster care, and mother Barbara Bohun eventually took her own life.

Extensive ground search

Casey lived in her Delta home along with her mother, Barbara Bohun, her mother's fiance Jonathan Poile, and her baby sister Stacy. The family had just moved to the area the month before.

Leeson says investigators have narrowed down Casey's disappearance to somewhere between about 2 a.m. and 9 a.m. on Saturday, Aug. 5, 1989.

A neighbour thought they may have seen the red-haired girl playing on her front porch that morning, but Leeson says that was never confirmed.

Casey's disappearance prompted police and dozens of volunteers to search the area around the home. Her mother and stepfather combed the area, searching through bushes and opening cupboards in garages, calling her name.

Three days later, police called their search off.

Leeson won't say who any of the suspects were, because the case is still active.

He says a few tips have come in over the years from people who thought they may have seen Casey in the Kelowna and Kamloops areas, but none of those ever panned out.

Family struggles

A flood of tips came when Leeson was first put on the case in 2001, after Barbara Bohun's suicide renewed interest in Casey's disappearance.

The mother and stepfather had separated, and Casey's younger sister, Stacy Bohun, was in foster care at the time.

In 2013, Stacy Bohun went to court after alleging that Tim Bachman, one of the founders of Canadian rock band Bachman-Turner Overdrive, sexually assaulted her when she was between the ages of 11 and 14.

At the time of the alleged sexual abuse, from 2000 to 2004, Bohun was a foster child living in Bachman's home in the Fraser Valley. Bachman was found not guilty.

'Very unusual' case

Crystal Dunahee says tragedies like a child's disappearance take their toll on families, often tearing them apart.

Dunahee went on to become the president of Child Find BC, a non-profit organization that provides free identification kits for children and advice for parents to keep their children safe.

Insp. Leeson says most missing persons cases are resolved within 24 hours, and across the country 92 per cent are solved within a week.

"To have a case where ... there's no indication of what's happened to that child is very unusual," he said.