Autopsies confirmed that a 47-year-old Michigan man shot his wife and all six of their children with a registered handgun, then set the family home on fire in what the Ottawa County Sheriff's Office has ruled a murder-suicide.

Kristopher Karolkiewicz used a handgun believed to be registered in his name to kill his wife, Amanda Karolkiewicz, 39, and six children ranging in age from 5 to 15 inside their Grand Haven Township home late last week. He then set fires in multiple locations throughout the residence before taking his own life, ABC News reported. All eight family members died from gunshot wounds.

The Ottawa County Sheriff's Office announced the findings Monday after completing autopsies on all eight victims. Capt. Jake Sparks said the office has closed the case to outside suspects and confirmed the fire was intentionally set after the murders.

"No suspects remain outstanding and the investigation shows that this was a murder-suicide, with a fire being started after the murders."

That was Sparks in a press release issued Monday. He added at a briefing that investigators believe the killings may have begun as early as Thursday night, the evening before fire crews first responded to reports of smoke in the area.

Fire crews responded twice before finding eight bodies

Friday morning, fire personnel arrived in the area after neighbors reported the smell of smoke. Crews could not locate a house fire and left. Several hours later, calls came in about white smoke rising from the Karolkiewicz residence. When firefighters entered the home, they found all eight family members dead in different bedrooms throughout the house.

The fire caused significant damage, particularly in the basement. Preliminary findings from Michigan State Police arson investigators indicate the blaze was set intentionally in numerous places throughout the interior of the residence, Fox News reported. The cause and origin remain under formal investigation.

Family pets, several dogs and at least one cat, also died in the fire.

The six children included four boys, ages 15, 12, 11, and 5, and two girls, both age 11. Four of the children were biological; two had been adopted. The sheriff's office has not released the children's names.

Sparks: 'This personally impacts dozens if not hundreds'

At Monday's briefing, Sparks spoke about the weight the case has placed on the community and on his own department. Grand Haven Township sits on Lake Michigan, west of Grand Rapids, a small community where a family of eight does not vanish without leaving a wide hole.

Sparks told reporters the office is still searching for answers, even with the criminal investigation effectively closed.

"We're trying to get answers for the family. We're trying to get answers for the community. We're trying to get answers for our own responders."

In a separate statement carried by Breitbart, Sparks expanded on the scope of the loss, saying the situation "personally impacts dozens if not hundreds of people in the county," including neighbors, co-workers, teachers, and students of Grand Haven Public Schools.

Domestic murder-suicides remain among the most difficult cases for law enforcement and communities alike. Just weeks ago, a Pennsylvania man fatally shot his wife before taking his own life in the woods behind their home, another case that left a community grappling with sudden, senseless violence behind closed doors.

Amanda Karolkiewicz remembered as a beloved teacher

Amanda Karolkiewicz, known to friends and family as "Mandy," was identified by relatives and community members as a teacher in the Grand Haven area. Grand Haven Area Public Schools issued a statement Saturday calling the incident a "tragic loss for our community."

"Our hearts are with all those impacted, and we know many throughout our community may be grieving and struggling to process this news."

The school district shared suicide and crisis hotline services for those affected.

Amanda's sister, Molly Cessna, posted publicly about her devastation. "My little sister Mandy, her husband, and my six nieces and nephews... Everything's just blurry. Our hearts are utterly shattered. Tragic doesn't even touch it," Cessna told the New York Post.

Amanda's stepfather, Steve Lawwill, said the family was "so grateful for the joy they brought into our life" and described the family as "just so shattered."

The grief rippling through Grand Haven is a reminder that the victims of violence within families are often the most vulnerable people in a community, children who had no say, no escape, and no warning. Cases like the recent killing of a 12-year-old boy in the Bronx and countless others underscore how often children bear the cost of violence they did nothing to invite.

No motive, and investigators say there may never be one

Authorities have not identified a motive for the killings. Sparks acknowledged at the Monday briefing that the community may never get a full explanation.

"This is an unspeakable tragedy that we may never completely understand why it happened. But we'll do our best to find the answers and to honor the memory of those victims."

The sheriff's office has not disclosed whether there was any known history of domestic violence, mental health crisis, or legal proceedings involving the family. The investigation into the fire's cause and origin continues through Michigan State Police arson investigators.

Cases in which a family member turns a weapon on the people closest to him, sometimes a spouse, sometimes children, sometimes both, occur with grim regularity in this country. A former youth pastor in Clark County recently died by suicide in jail after being charged in his wife's death years earlier. The pattern is consistent: sudden violence, shattered families, and communities left searching for answers that may never come.

What is known is this: a registered handgun, a house set ablaze in multiple rooms, and eight people, six of them children, found dead in their own bedrooms. The weapon was legal. The act was not. And the youngest victim was five years old.

Grand Haven Township is a quiet place on the shore of Lake Michigan, the kind of community where neighbors still look out for one another. What happened inside the Karolkiewicz home is the kind of failure no policy can fully prevent and no investigation can fully explain, but the people who have to live with it deserve every answer the evidence can provide.

Six children are dead. They deserved better than the man who was supposed to protect them.