DELPHI, Ind.–It’s been two years since Abby Williams and Libby German were murdered near the Monon High Bridge in Carroll County, and there are some things about the murders that only the killer knows. That’s an important strategy, said a retired Indiana State Police detective.

“Stoney” Vann worked for the State Police for 29 years and recently retired. He is best known for working on the Burger Chef murders.

“Ideally a murder investigation would be solved within that cliche’ time period of 48 hours,” he said, when asked why the case is still unsolved after two years. “Statistically the odds decrease on a successful outcome for every day past that, just speaking from a statistical standpoint.”

Vann could not speak to specifics about the Delphi case, but rather from his entire experience as an investigator.

“When there is no real connection or motive or reason why the crime was committed on its face, it can be very problematic in solving.”

Vann said if DNA evidence is collected, and the person who did it has never been arrested and has never submitted a DNA sample, then it is only logical that person will not show up in a database and the DNA evidence won’t be flagged.

So, a two-year wait, though not preferable, is not uncommon.

Audio titled STONEY VANN DELPHI INTERVIEW FEB 2019 by 93WIBC

Vann was also asked why police have not talked about the cause or manner of death for the girls. He said that’s not necessary info for the public to have. He also said it could stimulate unscrupulous people to waste valuable time and resources.

“False confessions happen often in cold cases. For one reason or another, there are some individuals, it could be mental issues, notoriety, it could be just wanting to be infamous for some reason,” he said. “They will research it, and if not much information is held from the public, they can speak very informed to the case.”

Vann said what state police are looking for is a tip that contains information the police have not spoken about publicly.

“Now you’ve got specific information coming in that was not released to the public. But, they’re speaking very informed to it. Now law enforcement can jump on that lead. So, we’re looking for that tip that really gets the attention of the police and that is someone who is speaking to the manner of death, when the manner of death has not been released.”

Vann said he believes police working on the Delphi case are getting more hopeful each day, not less, and that solving it is still very much within the realm of possibility.

PHOTO: Provided by Indiana State Police