They came from big cities and small towns. They ranged from toddlers to teenagers, and their family circumstances and upbringings varied widely.
They are Wisconsin's lost children — missing, endangered and the subject of painful memories for loved ones.
Some were taken by strangers. Others were likely victimized by someone they knew. A few might have died accidentally.
Some might still be alive.
The National Missing and Unidentified Persons System has identified 19 Wisconsin minors who disappeared and have never been found.
A USA TODAY NETWORK-Wisconsin examination reveals that the cases, which date as far back as 70 years ago, have left behind a trail of misery for grief-stricken parents, siblings and friends who struggle to come to grips with the sudden and unexpected loss of a child.
"I have spoken with a lot of family members from missing persons and the desperation and void they have is never filled," said Kenneth Mains, a detective in Pennsylvania who is a cold case consultant and president of the American Investigative Society of Cold Cases.
"It is absolutely heart-wrenching to see the pain they exude because they don't know," Mains said. "They don't know, and that is the worst part for them ... You must always remember that the missing person will always directly affect someone."
Two decades of hope
Next month will mark 21 years since 15-year-old Sara Bushland vanished near the end of her driveway after getting off her school bus in Washburn County. A high school sophomore in Spooner, Sara was 5 feet tall and weighed 104 pounds.
"She's a very loving person and there wasn't anybody that didn't like her," said her father, Mike Bushland, who lives in Chippewa Falls. "It would just be nice to have closure. Right now, yes, I think she's dead, but until we have a body, I still have to think she is alive someplace. That's all you can hope.
"All they kept saying was that she was a runaway. Quit calling them up and wasting their time and she'll show up. That's how sure they were. The police up there basically dropped the ball at the time, and there's nothing you can do about that now. All they can do now is learn from their mistakes."
Washburn County sheriff's officials in Shell Lake did not return a message seeking for comment for this story.
Some students on Sara's bus thought they saw an unfamiliar truck, either gray or dark green, approach her once she exited the bus near the end of her long driveway.
The idea that the 15-year-old ran away was ridiculous, her father said. None of her clothes were missing and there were no notes left behind. "She was the only thing missing," her father said.
"All you can hope is that somebody breaks down and openly says, 'I did it. I'm sorry, here's where the body is.' Who knows? It's an awful big world out there to find a little body. Right now, we just have no idea. It's going to be 21 years in April. A lot of people don't stay friends for 21 years so maybe now someone is more liable to say what happened. So far, that hasn't happened."
Investigation barriers
Only about 1 percent of missing children cases involve stranger abductions. Most involve juvenile runaways or small children taken by a relative, according to the National Center for Missing & Exploited Children.
The organization, started in 1984 by John Walsh and other child advocates, reported that it assisted families and law enforcement agencies on more than 20,500 cases involving missing children last year across the country — with 90 percent involving runaways.
Today, detectives are much better trained to properly investigate a missing child than officers who worked in the previous generation, said Mains, the cold case expert.
"The investigative methods are probably about the same, but the sense of urgency to disseminate the information is so much more effective, especially with the advent of social media," Mains said.
What does it take to solve a child abduction?
Thoroughness and solid interviewing skills are essential, said Patrick Solar, an assistant professor in criminal justice at the University of Wisconsin-Platteville. Far too often, he said, neighbors, immediate relatives, local businesses' workers and potential suspects are not properly interviewed at the outset of the investigation and solid leads never develop.
"If your working theory is a random or stranger abduction, I'd start with family and then expand to neighbors and widen that circle," said Solar, a former police chief in northern Illinois. " It's all about alibis and scratching someone off your suspect list. That should be your top motive. You don't want to waste any of your time on people with strong alibis."
Insufficient evidence
A $20,000 reward remains in place for information that helps the Antigo Police Department arrest and convict the person who kidnapped 15-year-old Kayla Berg, who was last seen alive eight years ago in central Wisconsin. (Photo: Antigo Police Department)
One of Wisconsin's most widely publicized missing children cases in recent memory is the Aug. 11, 2009 disappearance of Kayla Berg.
The 15-year-old Antigo girl was last seen with 24-year-old Kevin Kielcheski, a friend of Kayla's older brother. Kielcheski told police that he drove Kayla to Wausau, 40 minutes away from Antigo, to drop her off at an abandoned house owned by an acquaintance of hers, Miguel Marrero.
She was never seen or heard from again. That year, investigators in central Wisconsin impounded separate vehicles belonging to both Kielcheski and Marrero in hopes of finding forensic evidence of a violent crime. However, no blood or other significant evidence was recovered.
Antigo Police Detective Sgt. Dan Duley said Kayla's disappearance is probably the most frustrating case he has ever investigated.
At least a dozen different sites around Langlade, Lincoln, Marathon and Wood counties have been searched over the years, but neither the girl's remains, clothes, sandals nor her silver-ringed necklace has ever turned up.
"I would not say we're at a standstill," Duley said. "We're still reviewing the case. As far as keys for us? It could be information from another citizen or another law enforcement agency at this point."
Seeking tips from the public
Another of the state's missing-children cases involves the disappearance of Mosinee High School student Mackenzie Marken, who has not been seen since Oct. 11, 2015. She was 14 at the time she left her family's house in the village of Weston.
Weston is five miles from Wausau, where Kayla Berg was reportedly last seen in 2009. "There's no information to believe at this time that those two cases are related," said Everest Metro Police Detective Sgt. Dan Goff.
According to Marathon County Crime Stoppers, the last reported sighting of Mackenzie was on Oct. 16, 2015 near Mosinee's River Park and a short distance from the local high school property.
At no point has Mackenzie contacted any of her friends or family members to let them know she is safe. Her family and her siblings are hurting and wondering whether she's OK.
"We are still trying to locate her and bring her home safely," Goff said.
Tips from the public are crucial in hopes of solving the case, he said.
"I don't want people to be afraid to share information with us on any of these missing persons cases," Goff said. "People make assumptions what we know, but even with small amounts of information, you don't know what's important until you review it sometimes."
Technological advances
Unlike decades ago, resources are available statewide and locally to help police investigate cases of missing children.
Fox Valley Technical College's National Criminal Justice Training Center offers specialized training on AMBER alerts, Internet Crimes Against Children and child abductions.The college also offers online courses on missing persons, sex trafficking and human trafficking.
The Wisconsin Department of Justice operates a specialized Child Abduction Response Team of trained state investigators who can help local authorities investigate a missing child case. The DOJ also maintains Wisconsin Clearinghouse, a website with information on missing and exploited children as well as adults.
"We are another resource," said Jenniffer Price, director of the special operations bureau for Wisconsin's DOJ.
The state's criminal investigations analytical unit can be an important tool for local police agencies that find themselves dealing with an abducted child. "Even if we don't get a call, if we're aware of a case, we'll contact an agency," Price said.
Police agencies are better-equipped today to properly investigate an abducted child — and alert the public to any clues that could help catch the unknown culprit.
Price pointed to February's double murder of two teenage girls in Indiana to illustrate how far technology has assisted investigators. Police were able quickly to distribute a photograph of a man seen along the Delphi Historic Trails at about the same time that Abigail Williams, 13, and Liberty German,14, were last seen alive. Police also released an audio recording with the suspected killer's voice captured by one of the girls on her phone before she died.
"We didn't have that capability 20 years ago," Price said. "Law enforcement is putting the man's photo and his voice all over the media to see if anybody recognizes (him) ... Still, we need human intelligence to put these cases together."