FOND DU LAC COUNTY - After nearly 24 years, Fond du Lac investigators have identified a suspect in the murder of Berit Beck.
The 18-year-old was driving a van the day she disappeared.
Fond du Lac investigators now say they have evidence that shows a man was inside Beck's van, and that they know who it was.
Officials say the suspect is a 60-year-old Kenosha trucker. However, he is not in custody.
FOX 11 wanted to talk with investigators about the case, but they wouldn't comment Sunday.
Beck's mother, Diane Beck, says authorities told her about the new information over the weekend.
"About the only thing I probably want to share at this time is that there is evidence showing that this individual was someplace he shouldn't have been," said Diane Becker.
A search warrant says investigators gathered evidence from the man, including photos of his hands.
Detectives are now analyzing the photographs against other evidence related to Beck's van.
The van was found in a Fond du Lac parking lot just a few days after Beck vanished in the summer of 1990.
The Sturtevant teen was on her way to Appleton for work.
Her body was later found in a ditch near Waupun.
After more than two decades, Beck's mother says the new developments are still kind of shocking.
"For once it feels different than everything before. It's making us feel more confident that we're about to move ahead in this investigation," Becker said.
Diane Beck says she doesn't know where the investigation will lead, but she will continue to follow her daughter's case every step of the way.
"I suppose it's still a wait and see, but this is the best wait and see we've ever had."
The Fond du Lac County sheriff's office will hold a press conference updating the case Monday morning at 11:30.