John Ferak

USA TODAY NETWORK-Wisconsin

Killers often leave behind damning clues, but in two of Wisconsin's most high-profile murder cases, key fingerprint evidence led to drastically different verdicts.

In 2015, Fond du Lac County District Attorney Eric Toney charged Kenosha truck driver Dennis Brantner with the July 17, 1990 death of Berit Beck. The 18-year-old blonde-haired aspiring musician was abducted at a mall parking lot in Fond du Lac while en route to Appleton for a job seminar. Her body was found five weeks later, in a weedy ditch in rural Fond du Lac County.

Brantner was charged after Wisconsin Crime Lab examiner Karley Hujet identified nine of Brantner's fingerprints on five objects connected to the murder victim's conversion van. But the fingerprint evidence was not strong enough to convince a jury of Brantner's guilt. After three days of deliberations, the jury was unable to reach a unanimous verdict, and Fond du Lac County Circuit Judge Gary Sharpe declared a mistrial.

Toney later told the USA TODAY NETWORK-Wisconsin he intends to re-try Brantner.

On the other spectrum, fingerprint evidence presented during the 2007 murder trial against Steven Avery was largely beneficial to the defense. But a Manitowoc County jury still convicted Avery of murdering Halbach.

Wisconsin State Crime Lab Mike Riddle testified about the recovery of eight useful latent fingerprints from Halbach's turquoise-colored Toyota RAV4. The Hilbert woman's SUV was spotted along the outer perimeter of the Avery Salvage Yard by volunteer searcher Pam Sturm.

Avery was arrested, on Nov. 9, 2005. All of the fingerprint evidence that was identified from the RAV4 was compared against the fingerprints and palm prints of Avery.

"I think a total of eight locations," Riddle testified at trial. "... and those eight were eight latent lifts."

Fingerprint evidence came from multiple Aquafina bottles in the front of the RAV4, a black plastic CD case and a discarded granola bar wrapper in the back cargo area.

More prints were located in the rear of the vehicle, including near the tail light. A palm print was also discovered.

Inside, more fingerprints were found on an inside front passenger window and a back passenger window. Also, a fingerprint was lifted off the victim's hood.

"If somebody would open a hood, might touch it and leave a fingerprint?" asked Avery's lawyer Jerry Buting during the trial.

"That's correct," Riddle testified.

Initially, Riddle testified, special prosecutors Tom Fallon and Ken Kratz asked him to compare the slew of recoverable fingerprints and palm prints to Avery, their murder defendant.

"And they did not match, correct?" asked Avery's lawyer, Jerry Buting.

"No, they did not, that's correct," Riddle agreed.

Riddle also testified that prosecutors only asked him to compare the unknown prints to mostly members of Avery's extended family, including Avery's parents, his brothers Chuck and Earl, and Avery's nephews, the Dassey brothers.

None of the fingerprints matched them.

During the trial, Manitowoc County Circuit Judge Patrick Willis restricted Avery's lawyers from rattling off names of the potential murder suspects whose prints weren't compared with the unknown prints found on Halbach's vehicle.

"But am I correct that you did not, and have not, as of today, ever compared fingerprint standards from Lieutenant James Lenk or Sergeant Andrew Colborn to any of those fingerprints from the RAV4?" Buting followed up.

"I did not, you are right," Riddle testified.

Avery's lawyers argued Lenk and Colborn planted evidence against Avery including droplets of blood near the RAV4's key ignition and inside the passenger door. The pair also spotted a spare key to the RAV4 in Avery's bedroom. The key wasn't found during previous searches.

The jury found Avery guilty of killing Halbach despite the absence of fingerprint evidence tying him to her murder. He is serving a life sentence.

In contrast, Fond du Lac County prosecutors had solid evidence linking Brantner to their murder victim's vehicle: A soft drink cup from Burger King. A cellophane cigarette wrapper. A Jolen bleach kit from Walgreens. An employee training manual from Boldt Construction Co. The inside of a middle door window.

But other parts of their case were quite murky.

Where was Beck was murdered? What were the circumstances of her mall parking lot abduction? Why did her van have an extra 462 miles on it? Where did Brantner take her if he held her captive for so many hours?

In addition, the Fond du Lac County Sheriff's Office lost several crucial crime scene clues from its secured evidence storage unit.

Those missing or destroyed items included Beck's torn red shirt that she wore on the day of her abduction and knotted pantyhose to tie her up. Also misplaced were the socks, jeans and underwear that were found on Beck's body when it was discovered in late August 1990.

"I would hope that the jury was troubled by that; I am deeply troubled," Brantner's lawyer Craig Powell told USA TODAY NETWORK-Wisconsin on Friday. "The fingerprint evidence was clearly the most critical evidence.

"Without these prints, this case is never filed because there is nothing else that connected him to Miss Beck."

John Ferak of USA TODAY NETWORK-Wisconsin: 920-993-7115 or jferak@gannett.com; on Twitter @johnferak