Wilson was only married to serial killer Peter Tobin for three years (from age 16 to 19), but those were not easy years. Over the course of their marriage, Tobin would regularly beat Wilson. He was also known to bring home prostitutes and assault them in front of her. Despite the terrible treatment, Wilson never thought that Tobin would go on to be a killer.

Judith was married to Gary Ridgeway, also known as the Green River Killer. According to police, Ridgeway murdered at least 49 people, but his total number of victims could be double that. Mawson says that Ridgeway was a model husband and she only believed that he was a killer when he confessed to it.

Mary Elizabeth was married to killer Russell Williams, and she maintains that she never suspected her husband of his crimes. However, Williams apparently kept mementos from his killings in obvious places throughout the couple's two houses.

Brudos was the wife of serial killer Jerome Brudos. Darcie ignorned some very obvious clues about her husband's deadly activities, including the time he brought home an actual human breast, cast in resin, to use as a paperweight.

Linda was married to brutal killer Robert Yates. During his spree, Robert killed at least 13 prostitutes. Despite the clues, Linda never suspected that her husband might be a killer at any point in their 26-year marrage until the police told her.

Chikatilo was married to the so-called Butcher of Rostov — also known as the Red Ripper — Andrei Chikatilo. Andrei brutally murdered, mutilated, and raped at least 52 women and children. It's likely that Fayina knew deep down that her husband was a killer, but she was terrified of him and refused to acknowledge it until police confronted her with the evidence.