Police identify mother, son as 2 killed in Mercer Island murder-suicide investigation

Details emerge in Mercer Island murder-suicide investigation

Four family members are dead in a homicide investigation spanning two cities in King County, with police believing the murder-suicide was carried out between two homes miles apart in Issaquah and Mercer Island.

KING COUNTY, Wash. - Police have identified a mother and son found dead during a welfare check at a Mercer Island home, as investigators continue working to determine the circumstances surrounding their deaths and two additional deaths in Issaquah.

The Mercer Island Police Department said officers were sent around 10:45 a.m. Dec. 30 to a residence in the 8400 block of Southeast 46th Street after an attorney representing the homeowner reported receiving a concerning email that raised fears for the occupants’ safety. 

When officers arrived, they looked through a window and saw a person inside the home who appeared to have suffered a gunshot wound. Police entered the residence and found two people dead, a woman in her late 70s and a man in his late 40s, both with gunshot wounds, according to the department. Firearms were found inside the home and near the individuals.

Based on preliminary information, police said the incident appeared to be a homicide followed by a suicide. Authorities said there was no indication of an ongoing threat to the community.

Identities released by Mercer Island police

In an update on Dec. 31, Mercer Island police confirmed the identities of the two people found dead at the Mercer Island home.

The woman was identified as Danielle Cuvillier, age 80. The man was identified as her son, Makenzie P. Williams, age 45. Police said both were identified using Washington state driver’s licenses.

Investigators are continuing to work with the King County Medical Examiner’s Office to determine the official cause and manner of death.

(FOX 13 Seattle)

Firearms recovered as part of the investigation

Police said four firearms were recovered from inside the Mercer Island residence. An additional firearm was found inside a vehicle that was impounded as part of the investigation. All the firearms will undergo forensic analysis, according to the department. 

Authorities said the forensic process will take time and that results will be released when they become available.

Issaquah welfare check followed Mercer Island discovery

After the initial discovery in Mercer Island, investigators identified concern for another person who had previously lived at the home, police said.

As a precaution, Mercer Island police requested that the Issaquah Police Department conduct a welfare check at a separate residence in Issaquah.

Officers later found two additional people dead at the Issaquah home. Authorities have said the individuals were related to the mother and son found in Mercer Island. Police reported no signs of forced entry at the Issaquah residence.

Investigation continues

Detectives from Mercer Island and Issaquah are continuing to investigate the circumstances surrounding the deaths, with assistance from the Washington State Patrol Crime Scene Response Team.

Police have said they do not believe there are any other suspects and that there is no indication of a continuing danger to the public.

"The investigation remains ongoing," the Mercer Island Police Department said in its latest update. "Additional information will be provided as it becomes appropriate to do so." 

The King County Medical Examiner’s Office will determine the official causes and manners of death for all four individuals.

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