NEWSTEAD, N.Y. (WIVB) — Four members of a family are dead after a series of shootings in eastern Erie County.

Two women, identified as Mary Beth Bergum, 37, and 64-year-old Nancy Bergum, were found dead in two separate homes in the Town of Clarence, according to the Erie County Sheriff’s Office. Mary Beth’s husband and Nancy’s son, 43-year-old Erik Bergum, is believed to have shot each of them, the Sheriff’s Office said.

Sheriff John Garcia says it’s believed that Erik Bergum then went to Ten-X Shooting Club at 8081 Greenbush Rd. in the Town of Newstead, where he fatally shot his father, 66-year-old Mark Bergum, before turning the gun on himself.

Erie County District Attorney John Flynn says there was a witness to what happened at the shooting range. The father apparently told that witness that Erik was going to join him there at some point. Erik began to shoot at the range before firing upon his father, Flynn said.

“There is no indication that the father was aware of what the son just did,” Flynn said. “Absolutely none.”

On Thursday, News 4 crews saw an active investigation at a home in Clarence. Sheriff’s deputies were seen taking a gun and other items from the home. It’s not clear if the same weapon was used in each shooting incident.

Erik and Mary Beth were living together before their deaths.

In Eric’s vehicle, Garcia says a note, which was “difficult to decipher,” contained a plan. But the motive behind this series of shootings is not clear, Flynn said. It’s also not completely clear how far ahead this was planned, but at a minimum, they believe it was planned by Thursday morning.

“The note appears to have been written all at one time,” Flynn said.

As a result of this incident, four children were left behind. They were all in school at the time of the shootings. Flynn says they’re currently staying at a friend’s house.

“My concern is what’s going to happen to these four children now going forward,” Flynn said, noting that they don’t have much family in the area.

Erik Bergum had an insurance fraud conviction from 2011. Flynn says he was “in the home theater business” with a partner. A welfare check was conducted on the partner, who is okay.