Four family members—a mother, her two sons, and a daughter-in-law—were found dead in two homes near Seattle in a suspected murder-suicide on December 30, 2025. The Mercer Island Police conducted a welfare check at Danielle Cuvillier’s, 80, and her son Mackenzie P. Williams’, 45, residence after a concerning email from her attorney. Officers discovered the two with gunshot wounds and multiple firearms nearby.
Additional Discoveries
Issaquah Police checked another family property, finding a mid-40s woman (Williams’ wife) and a mid-30s man (Cuvillier’s youngest son with Angelman syndrome) dead, with no forced entry or suspects outstanding. No community threat identified; autopsies pending from King County Medical Examiner.
Family Conflict
Tensions brewed over a year amid disputes on the younger son’s 24-hour care needs. Williams accused Cuvillier of abuse (denied); she gained guardianship in November 2025. Recent clashes involved denied visits, a 911 call, assault charge against Cuvillier, and her protection order petition citing Williams’ aggression and his firearms.
