An Oregon man whose wife filed for divorce in May is suspected of killing her and their two children on the Fourth of July at their home and then committing suicide, police said Thursday.

The four family members were found dead Wednesday after a caller told police about an alarming post on a social network.

All four had been shot, police said. An autopsy is planned Thursday.

Investigators believe that 37-year-old Randall Engels killed 35-year-old Amy Engels and their school-age children, said Capt. Jeff Kosmicki of the Newberg-Dundee police.

The family had lived for several years in Dundee, about 25 miles southwest of Portland along Oregon 99W, known for weekend and holiday traffic bound for the vineyards and tasting rooms of the region.

An index of court filings shows Amy Engels filed for divorce on May 29. Other details of the filing were not immediately available. Police didn't name the children.

Neighbors who would speak to journalists knew little about the family members.

The neighborhood has modest one-story, single-family homes bordered by vineyards. Outside the Engels home on Thursday sat two vehicles, a pickup and an SUV.

Neighbor Kelley Wood said there was little chance that gunfire would have been noticed on Wednesday, given a nearby gun club, the percussive devices used in the vineyards use to scare off deer, and the holiday. On Thursday morning, the remains of fireworks littered an intersection near the family's home.

"There were a lot of noises that could have sounded like gunshots," Wood said.

Joe Endicott, an 18-year resident, didn't know how many years the Engels had lived there, but he said their tenure was longer than most residents there.