‘Danielle adored Nick’: Friend remembers mother killed in triple murder-suicide

Four people were recently killed in a murder-suicide in Mercer Island and Issaquah. The four were identified as 80-year-old Danielle Cuvillier, her son, 45-year-old Mackenzie “Mack” Williams, her other son, 34-year-old Dominick “Nick” Cuvillier, and Mack’s wife, 44-year-old Harmony Danner.

Mack had previously told police that Danielle was abusing Nick, who was severely disabled, but Danielle’s friend of more than 30 years painted a different picture.

“Danielle adored Nick,” Laurie Fairman told MyNorthwest via email. “This was obvious to all who knew her. She went to great lengths to maintain his well-being with respectful, responsible diet, plenty of entertainment such as puzzles, screen games, a whole man cave for watching movies, not to mention plenty of social interaction.”

Authorities ruled Mack’s death a suicide. Danielle, Nick, and Harmony were killed by gunshot wounds in what was ruled a triple homicide.

Court records reveal troubled family history

King County court records, provided by Shawn Garrett with KIRO 7, revealed a history of turmoil in the family.

Mack stated his mother filed a petition against him, “to keep me away from my brother so that I cannot be a witness to her abuse and mistreatment of him and to prevent me from being able to advocate for my brother,” according to court records.

Mack’s father was Nick’s primary caretaker until he died in 2018, leaving Mack and his mother to a shared caretaking arrangement for Nick, court records stated. Mack claimed his mother had “serious anger issues,” and he believed Nick was being physically abused.

Danner also testified that she witnessed Danielle physically abusing Nick multiple times, according to court records.

Friend says Danielle was an ‘impressive’ mother

But Fairman stated, “Danielle looked after her son Nick in ways that I found impressive.”

“When he displayed signs of gastric pain some eight to 10 years ago, it was Danielle who suggested to the doctors that they look into the possibility of Celiac disease,” she added. “She was right.”

Fairman said Mack stole gold from Danielle that she had bought to protect Nick as an investment.

Fairman also accused Mack of lying to authorities, saying that “with the slightest bit of effort, they would have seen that there was much more to the story and that Mack in fact presented a far greater source of danger than his mother.”

But she noted, “Danielle never wanted to believe that there was anything wrong with her boys.”

911 call led to Danielle’s arrest

In a 911 call, obtained by KIRO 7, Mack told the operator that Danielle attacked him and that he was holding her to the ground. Danielle is heard screaming in the background.

“The last thing I remember clearly was me asking him if he wanted to go to my house, then she started attacking me, then at that point it was just stop, back off,” Mack told the Mercer Island Police Department, according to KIRO 7.

Danielle was arrested, sparking the months-long legal battle over the custody of Nick.

However, Fairman said Mack was a large man, while 80-year-old Danielle couldn’t have weighed more than 125 pounds, claiming Danielle couldn’t have beaten him up.

“I stand by my word; she was a tireless mother who protected and took great care of her second son, Nick, and that Mack was a psychopath who lied,” Fairman stated.

Mack and Danielle were found dead in a home in Mercer Island, and Nick and Harmony were found dead in a home in Issaquah on December 30.

Contributing: KIRO 7

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