The most bizarre theory from Netflix's new true crime hit, The Staircase, explained.

The death of Kathleen Peterson on December 9, 2001, has provided a wealth of true crime fodder and facts for fans of the genre to really sink their teeth into.

The story of her death, and the following trial of her husband who was accused of her murder, resulted in Dateline segments, a Lifetime movie and dozens of true-crime television episodes and dedicated podcasts.

Now, fascination with the puzzling case has been renewed, thanks to a revamped documentary series called The Staircase, which has just dropped on Australian Netflix. The first eight episodes of the series were released in 2004 and now brand-new episodes with fresh information have been added to the series.

The Staircase follows the compelling story of Michael Peterson, a crime novelist who was accused of killing his wife Kathleen after she was mysteriously found dead at the foot of a staircase in their home in Durham, North Carolina, with lacerations to her head and surrounded by a pool of her own blood.

Peterson was arrested and found guilty of first-degree murder, leading to a life sentence that was eventually overturned because of a plea deal.

However, along with evidence that pointed towards Peterson’s involvement with his wife’s death, another slightly more bizarre theory was also put forward for consideration.

During the trial, lawyer and businessman Larry Pollard insisted he had unearthed a State Bureau of Investigation report that would see his former neighbour, Peterson, released from prion. For more than four years, Pollard had been insisting that an owl was responsible for Kathleen’s death, believing that the bird had caused the extensive blunt-force trauma and head wounds that had resulted in her death.

To prove his theory correct, Pollard stood outside the Durham County Courthouse and faced a crowd of TV crews and newspaper reporters and explained his theory. He even went as far as to use stuffed owls as props to back up his explanation.

The film crew that produced The Staircase were also on hand to catch Pollard’s news conference.

If you’re looking for a juicy new Netflix show to sink your teeth into, The Staircase is really the only option. 

“The District Attorney’s Office dismissed it as absurd, citing the absence of feathers, and most people labeled it as ridiculous,” Pollard said at the news conference. “Always the same question was asked by the authorities and the press: ‘Where are the feathers?’ Well, folks, we are here today announcing the feather has been found.”

An SBI report lists the presence of a microscopic feather mixed in with hair that Kathleen Peterson had clutched in her left hand. Microscopic feathers were discovered in her hair as well as wood splinters and cedar needles. Theory believers felt that the wounds on her head could have been caused by talons.

Then there is the added evidence that Barred owls (the type of bird that is suggested to have caused the injuries) were native to the Durham suburb that the Petersons called home, and according to local news outlets, owls attacking joggers in that area was not an uncommon occurrence.

However, there are some strong pieces of evidence that explain why  “the owl theory” is not entirely plausible.

The first is that it was reported that Michael and Kathleen had spent time outside together in the day before her body was found, which would explain how the debris, such as the microscopic pieces of feather, had found their way onto her body.

And, as we see chronicled in The Staircase, an owl attack also wouldn't account for the bruising that was found on Kathleen's face and arms. It was speculated that her wounds were in fact defensive marks, or perhaps evidence that someone had tried to strangle her.

According to the series, state medical examiner, Dr. Deborah Radisch, told jurors during the 2003 trial that Kathleen had crushed thyroid cartilage, which "suggest someone tried to manually strangle her." This also goes a long way towards proving that an owl was not the cause of her death.

So, where could those feathers have come from?

Well, there is the theory that the very small piece of feather could have in fact just been goose down, which is often found inside pillows and comforters.

During The Staircase, David Rudolf, who was one of Peterson's original attorneys, said the owl theory was not completely outside the realm of possibility, but there was not enough evidence on hand to really make it plausible that a bird was responsible for the death.

"If you ask me what's the most likely scenario? I'd say it's a fall," Rudolf says in the series' penultimate episode. "Can I rule out that it's an intruder? I can't. No one can. You can say there's no evidence of that, but it's well known that the absence of evidence is not evidence of absence, so we don't know. Can I say 100 per cent that it wasn't some raptor who flew down and inflicted those scalp wounds without causing a skull fracture or any brain injury? I can't say one way or another."

So, even though this bizarre theory presented to us in The Staircase does have a small touch of evidence behind it, at the end of the day it cannot be proven as fact.

All 13 episodes of The Staircase are available to watch now on Netflix.