The Staircase: Chilling Truth About Kathleen Peterson's Injuries

The Staircase is an eight-part true crime series that has aired exclusively on Sky Atlantic about Michael Peterson, a novelist convicted of murdering his wife Kathleen, whose body was found at the bottom of the staircase in their home.

Kathleen died in December 2001 and Peterson has always maintained his innocence, even after he was sentenced to life in prison without the possibility of parole in October 2003.

During the trial, which has been relived through Netflix's own docu-series which shares the same name as the Sky Atlantic series, the defence and prosecution debated Kathleen's injuries and argued whether the amount of blood found at the crime scene was consistent with someone falling down the stairs.

Peterson claimed that on the night of her death, the couple had enjoyed drinks by their pool after dinner.

Kathleen went inside first and he followed after some time had passed and found her lying by the foot of the staircase covered in blood.

He was the only other person in the house at the time and was immediately treated as a person of interest by investigators.

The defence argued that the lack of cast-off spatter at the scene suggested no weapon was used in her death, otherwise Kathleen would have suffered bruising and skull fractures.

However, the prosecution argued that Kathleen had suffered blunt-force trauma. 

The autopsy found seven lacerations to the top and back of Kathleen's scalp, which caused her to bleed out, but there was no skull fracture found.

Kathleen also had an injury to her thyroid cartilage, suggesting she may have been strangled.

Forensic expert Henry Lee, hired by the defence, testified that the blood spatter evidence was consistent with an accidental fall down the stairs. 

Police investigators, however, came to the conclusion that the injuries were inconsistent with such an accident.

Medical examiner Dr. Deborah Radisch ruled Kathleen's death a homicide likely as a result of an assault, writing: "Severe concussive injury of the brain caused by multiple blunt force impacts of the head [caused her death]."

She further explained: "The number, severity, locations and orientation of these injuries are inconsistent with a fall down stairs; instead, they are indicative of multiple impacts received as a beating."

In 2017, Peterson entered an Alford Plea and his life in prison sentence was overturned to time served. An Alford Plea is when someone admits technical guilt while maintaining innocence in exchange for freedom.

The Staircase is available to stream on Sky Atlantic in the UK and HBO Max in the US now.