DEXTER, Maine — A Harmony man who was upset that he had not been allowed to attend his son’s eighth-grade graduation later this week shot and killed his estranged wife and their two children Monday before committing suicide, Maine State Police said.

The bodies of Steven Lake, 37, Amy Lake, 38, and their children Coty, 13, and Monica, 12, were found in the living room of the first floor of a house at 173 Shore Road, according to Maj. Gary Wright of the state police. It appeared all had died from shotgun wounds, he said.

“It was clearly a domestic violence homicide,” Wright said.

The Lakes had been feuding for the past year and were in the process of getting a divorce. Steven Lake was scheduled to be tried in Piscataquis County Superior Court in July on four charges, including criminal threatening with a dangerous weapon and domestic violence criminal threatening. Police said he threatened his wife on June 14, 2010, in Wellington. As part of his bail conditions, Lake was ordered not to have any contact with Amy Lake.

On Nov. 11, 2010, Lake was charged with violation of bail and violation of a protection order for allegedly having contact with his wife. She appeared to have obtained a protection from abuse order, which is in effect for a year, after the June incident.

Family members said Amy Lake, a beloved kindergarten teacher at Ridge View Community School in Dexter, moved a couple of times to try to avoid her husband and had recently rented the Shore Road home.

At around 8 a.m. Monday, a Dexter police officer, Sgt. Kevin Wintle, went to the home for a well-being check on Amy Lake after a friend of the family observed Steven Lake’s vehicle in her yard. The caller also reported that neither Amy Lake nor her children had showed up for school, according to Wright.

When Wintle arrived at the home, he heard multiple gunshots in succession from inside so he secured the perimeter and called for backup. Wintle does not believe he was fired at, Wright said.

Late Monday afternoon, Wright said it was clear to police that Wintle interrupted Lake’s plan to set the house on fire after he killed his family because police found accelerants throughout the house.

Law enforcement officers from several agencies, including the Maine State Police Tactical Team, state troopers, Dexter police, Piscataquis, Penobscot and Somerset County sheriff’s deputies, and game wardens, responded to Wintle’s call.

Negotiators from the state police “tried in vain for over two hours to contact Lake” by phone and loudspeaker, according to Stephen McCausland, spokesman for the Maine Department of Public Safety.

Just after 11:30 a.m., a state police negotiator using a loudspeaker asked “Steven” to pick up the phone in the house. “We want to make sure everyone is OK,” the negotiator said.  “I want to hear your side of the story. No one is going to hurt you. If anybody’s hurt, we can help you.”’

The negotiator repeatedly said: “Please pick up the phone. Tell me what’s going on. A lot of people out here are concerned.” He urged Lake to let his children go outside. “They’re great kids and they’ve done nothing wrong and I know you want to protect them.”

Police attempted to talk to Lake for several hours but never established any contact.

At about 12:30 p.m., an armored tactical vehicle, with a battering ram attached, could be seen moving up the driveway toward the house. “One more chance to pick up the phone,” the negotiator said over the loudspeaker. “One more chance or we’re coming in.”

Several minutes later a big boom could be heard and then the armored vehicle backed away from the two-story house and police attached a ladder to the front of the vehicle.

The tactical team made entry into the house at about 2 p.m. and observed the four bodies, Wright said. A dog, which was left behind in the house, was alive, he noted.

A state medical examiner was on scene late Monday afternoon and confirmed that all four people died of gunshot wounds, Wright said. He said additional examinations of the bodies will be conducted Tuesday. An evidence technician also was at the scene Monday afternoon, he added.

Police intend to interview family members and friends further to find out what prompted the domestic violence killing, according to Wright.

Mylon Lake of Harmony, Steven Lake’s uncle, said Lake and his wife had been separated for about a year. He said he knew his nephew was extremely upset because his wife would not let him see the children. But “I didn’t know this was coming,” he said of the murder-suicide.

“What really dumped him over the edge was the fact he couldn’t go to his son’s graduation,” Mylon Lake surmised Monday afternoon at the scene. “He kinda flipped out after that. You push a button long enough and things will come to a head.”

According to the uncle, Lake had been unable to see his children in recent months. It was a bad relationship his nephew had with his wife and that relationship caused him to lose his business, Lake Heating in Harmony, as well as his children, Mylon Lake said.

Phil Kreider, a neighbor of Amy Lake’s, called the killings “very shocking.” He said he had moved from Los Angeles to get away from crimes like this. He said he moved to the dead-end street because it was quiet and nice.

The tragedy in Dexter is the fourth incident of domestic violence-related homicide in Maine this year, according to statistics compiled by the Maine State Police. Homicides are considered domestic violence when they are carried out by a family member, spouse, partner or former partner of the victim.

On June 6 in Winslow, Nathaniel Gordon chased his wife, Sarah Gordon, 30, down Marie Street with a handgun, shooting her several times and ending her life in front of a neighbor’s house. Gordon, 32, then fled in his wife’s car and later shot himself to death in Gray after a police chase.

On May 24, Skowhegan police found Marie Flewellan, 75, and her husband, Barbour Flewellen, 86, dead in their bed shortly after Barbour Flewellen called 911 to report “two mercy killings.” Police believe that Barbour shot his wife before turning the gun on himself.

On May 1, Steven T. Mayo, 22, of Dover-Foxcroft, allegedly shot his brother, Ryan Mayo, 20, who lived next door. Steven Mayo is charged with intentional or knowing murder.

The deaths of Amy, Coty and Monica Lake bring the number of homicides this year in Maine to 10, according to McCausland. That number does not include the death last Thursday of a Bangor man on Fourth Street, or the death Monday of a Bangor man on Ohio Street, both of which have been called suspicious by Bangor police.

Crime statistics released last month by the Maine State Police said there were 24 homicides in 2010, nine of which were domestic violence-related. Of the 26 homicides in 2009, eight victims died at the hands of a blood relative, according to the Uniform Crime Report for that year.

BDN writer Judy Harrison contributed to this report.