Four killed by Washington state gunman included his wife, her two sons

(Reuters) - The four people killed by a Washington state man who later fatally shot himself were his wife, her two adopted sons and a neighbor, the Mason County Sheriff's Office said on Saturday, a day after the shooting in a rural home west of Seattle.

The sheriff's office chief deputy said the gunman, David Wayne Campbell, 51, had "an extensive criminal history."

"He was an evil man," Chief Deputy Ryan Spurling said.

Campbell shot and killed himself in front of police after an hours-long standoff with a SWAT team after calling police to the property in Belfair, about 25 miles (40 km) west of Seattle, according to the sheriff's office and the coroner.

Mason County Coroner Wes Stockwell, in a statement, identified three of the victims as Lana Carlson, 49, and two boys, ages 16 and 18.

Carlson and the two boys were found dead in an out-building on the property, along with a fourth victim who has not yet been named but is believed to be a neighbor, the sheriff's office said.

The lone survivor, a 12-year-old girl, escaped or was released by the gunman before he emerged from the house.

Spurling said the sheriff's office was working to confirm that the girl was also an adopted child of Carlson's.

Police arrived at the home after Campbell called a sheriff's sergeant on the officer's work cell phone to say that he "did something" and asked that authorities be sent to the residence.

It was not explained how the suspect knew the sergeant's phone number, but Spurling said "the gunman did have a previous contact with the sergeant."

The latest round of deadly U.S. gun violence came a day after a man near Wichita, Kansas, fatally shot three people and wounded 14 before being slain by police at a Kansas lawnmower factory where he worked.

(Reporting by Victoria Cavaliere; Editing by Leslie Adler)