Investigators discover novelist Michael Peterson clutching his dead wife, Kathleen, at the bottom of their back staircase. Peterson insists her death is the result of a tragic fall, but investigators believe otherwise.

Investigators discover that 16 years ago, Michael Peterson's friend Liz Ratliff also died at the bottom of a staircase, lying in a pool of blood.

Michael Peterson's defence unveils a long sought-after piece of evidence, catching the prosecution off guard. Bombshell revelations about an expert witness threaten to unravel the entire case and give Peterson a shot at freedom.