The sister of a Lake Elmo teenager who went missing 30 years ago said Friday that her family had endured "crushing pain" not knowing her whereabouts for all those years.

"Grandparents, aunts and uncles, all passed away with only one wish — to know what happened to Sue," said Christine Swedell, the younger sister of Susan Swedell, who disappeared on Jan. 19, 1988.

Washington County Sheriff Dan Starry held a news conference Friday to announce that solving the mystery is the first task for his new cold case unit. "Today is about Susan," he said. "Today is about hope. We're determined to find a resolution for the family."

Joining Starry at the news conference, in addition to Christine Swedell, were Chief Deputy Brian Mueller, Investigations Commander Andrew Ellickson, County Attorney Pete Orput, County Commissioner Gary Kriesel, Superintendent Drew Evans of the Minnesota Bureau of Criminal Apprehension and three detectives working on the case.

"We're never going to let go of this until we can hold someone accountable to answer the questions," Orput said.

To draw more attention to the Swedell case, a walk will be held at 10 a.m. Saturday at Maplewood Mall, starting near the entrance to Kohl's, Starry said.

The night she disappeared, Susan Swedell, then 19, finished work at Kmart in Oak Park Heights and began driving home in the middle of a snowstorm. She had changed out of her work uniform and left work with no coat.

A few miles down Hwy. 5, she pulled into a gas station because her car was overheating. She asked an attendant where she could park her car, then the attendant watched her climb into a car driven by a tall, unshaven man. The car headed west toward downtown Lake Elmo. It was the last time anyone reported seeing her.

Christine Swedell, who was 16 when Susan disappeared, said the sisters were finding happiness again after their parents' difficult divorce.

"Why would everything have to be tragically pulled apart by pure evil on the night of Jan. 19, 1988?" Christine Swedell said. "Every single day feels like a living hell without her. I can still feel the touch of her hand, hear her soft-spoken voice, hear her laugh, and all the while someone out there knows what happened to my dear Sue. It's unbearable and sickening."

Starry said the unit will review the entire Swedell case, with detectives re-interviewing witnesses and looking to uncover new information. They have completed about 25 interviews, he said.

Investigators are approaching Swedell's disappearance as both a missing-person case and one that could involve foul play, he said, because "there's just not a lot of information out there about what happened that night."

A statewide billboard campaign has produced as many as 20 new tips, Starry said.

Evans said about 35,000 Minnesotans are reported missing each year, most of them juvenile runaways and vulnerable lost people who are located after a short time.

Starry said that anyone with information about Swedell's disappearance should call the Washington County Sheriff's Office tip line at 651-430-7850. A $25,000 reward has been offered for information leading to her recovery.

"We want to make sure we leave no stone unturned," Starry said.