Police say the cases are linked to a Mercer Island residence and there is no ongoing threat.
MERCER ISLAND, Wash. — Police found two people dead inside a Mercer Island home Tuesday morning and, less than an hour later, two more at an Issaquah address reached for a welfare check requested by Mercer Island investigators. Detectives said the deaths appear connected and that the initial scene is being investigated as a homicide followed by a suicide.
Authorities said the chain of events began after an attorney contacted Mercer Island police about a troubling email from a client, prompting officers to check a house in the 8400 block of Southeast 46th Street at about 10:45 a.m. Tuesday. Inside, officers found a woman in her late 70s and a man in his late 40s, both with gunshot wounds; firearms were recovered nearby. As detectives worked the scene, they flagged concerns about another person linked to the address, which led Issaquah police to a second welfare check and the discovery of two more bodies. Investigators emphasized they were not seeking additional suspects.
Mercer Island Police Commander Jeff Magnan said investigators are treating the Mercer Island deaths as a potential homicide-suicide while keeping an “open-minded” approach to the evidence. “We’re not looking for anyone; we believe both individuals are inside,” Magnan said. “It’s very unfortunate. This hits our community very hard.” Issaquah officers, responding around 11:37 a.m. to the 400 block of Southeast Evans Lane, found a woman in her mid-40s and a man in his mid-30s dead inside a home with no signs of forced entry. Washington State Patrol’s Crime Scene Response Team joined local detectives to process both addresses for firearms, casings, electronic records and other physical evidence. Officials said there is no indication of an ongoing threat to the public.
Police did not immediately identify the four people or describe their relationships beyond the Mercer Island pair being an elderly mother and her adult son, according to initial statements at the scene. Detectives said the second address came into focus because of ties to someone who had previously lived at the Mercer Island home. The sequence of gunfire is still under review, and officials have not said who fired the shots. Investigators are examining email communications that triggered the first welfare check and canvassing the surrounding blocks for doorbell footage and witness statements. No neighbors reported hearing gunshots Tuesday morning, according to preliminary accounts.
Records show the Mercer Island neighborhood sits a few blocks north of Island Crest Park, in a residential pocket of single-family homes, and the Issaquah address is part of a cul-de-sac just east of downtown. Both scenes remained taped off for hours Tuesday while forensic teams mapped the interiors and collected items for ballistics and DNA testing. The King County Medical Examiner’s Office will confirm the identities and causes of death and determine manner of death for each person after autopsies and next-of-kin notifications. Police said they will release more details once the medical examiner’s rulings are complete and after investigators finish interviews with relatives and associates.
Detectives described Tuesday’s work as a multi-agency effort spanning two cities. Officers checked nearby properties, photographed tire tracks and footprints, and removed several paper evidence bags from the Mercer Island home by midafternoon. In Issaquah, investigators focused on the home’s entryway and a rear room while officers diverted traffic on Southeast Evans Lane. “Our hearts go out to the families,” an Issaquah police spokesperson said at the scene, adding that neighbors had been cooperative and patient as crews worked through the day.
As of Tuesday night, police said no suspects were at large and that the investigation would focus on timelines, firearms tracing and digital communications linked to the Mercer Island residence. The medical examiner’s office is expected to issue identifications in the coming days. Detectives plan to review lab results and body-worn camera footage before scheduling additional briefings. The next update from Mercer Island police is expected after autopsy findings are released.
Author note: Last updated December 31, 2025.