The boy was later identified as Jordan Stewart. The couple's other child, a 10-year-old daughter, was later found safe in Oregon, said Pierce County sheriff's spokesman Ed Troyer.
The boy's body was discovered in the family's home in the 1100 block of 178th St. Ct. East in Spanaway Tuesday afternoon, Troyer said. Troyer said the man who committed suicide was not the child's biological father.
Investigators said the inside of the home had signs of violence and the boy was found dead in an upstairs bedroom.
“Definitely some kind of issue going on in this residence,” Troyer said. “TVs are destroyed, house is trashed. There's nothing in this house that is not in disarray.”
Tuesday morning, a fleeing driver committed suicide as a high-speed chase came to an end on Interstate 5 at Tumwater, and troopers found a woman's body in the passenger seat moments later. The woman was later identified as 38-year-old Kristy S. Sampels.
Kristy Sampels and David Stewart
The trooper attempted to pull the driver over, but the driver kept going and a chase began. The chase reached speeds of 105 mph as the driver weaved in and out of traffic, Gill said.
The driver continued on I-5 south through Olympia but troopers deployed a spike strip and the driver eventually lost control, spinning out just past the Tumwater Boulevard exit and coming to a rest right in front of the trooper's car.
The trooper says he saw the driver raise his hands and then heard a gun shot. Gill says troopers then found the driver, 38-year-old David F. Stewart, dead from a gunshot wound.
Investigators found a gunshot wound on Sampels' body, but believe she was shot prior to Tuesday's incident.
No shots were fired by any troopers, Gill said.
The news of the deaths came as a shock to the family's neighbors who held a candlelight vigil for the victims on Tuesday night.
"To hear they found him here and he was dead -- my heart just left my body," said neighbor Allen Carter.
Neighbors said the couple moved in about a year ago and Sampels was often ill.
"Just she was sick," said neighbor Chari Carter. "I don't know what was wrong."
IV bags were found inside the home along with medication, and crutches were in the car when it crashed.
"That's something pretty deep there," said neighbor Phillip Douglas. "I wouldn't understand it. I wouldn't understand it myself."