MADISON, Wis. -- Madison police said the case of a murder-suicide involving a father and his son is closed. On Friday, the family said it wants to turn to focus to 12-year-old victim Kyle Dutter and why he will be missed.

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Police said there is still no clear motive as to why Ryan Dutter, 36, fatally wounded his son, Kyle Dutter, and then turned the gun on himself.

Officers found the two mortally wounded inside a sport utility vehicle parked at Haen Family Park on Madison's far West Side Tuesday morning. Kyle Dutter died later Tuesday, and Ryan Dutter died Wednesday from a self-inflicted gunshot wound.

Kyle Dutter's sister and mother said Friday they are still coming to grips with the tragedy. They said they want Kyle to be remembered for who he was and not how his life was cut short.

"He just, anything he loved, he just continued to love. He loved Halloween. He'd talk Halloween all year long. At Christmastime, we could drive and he could watch Christmas lights for hours," said Kimberly Dutter, Kyle Dutter's older sister.

On Friday afternoon, Kimberly Dutter spoke of her brother and how she feels he affected the lives of everyone he met.

She described a child who loved to be around people. Kimberly Dutter said he always said "hi" to everyone and couldn't understand why some didn't return the favor.

While Kyle Dutter was autistic, Kimberly Dutter said she just remembers him as her younger brother. Kimberly Dutter was 6 years old when Kyle was born.

"He concentrated a lot on the little things in life that a lot of other people forget. They meet him, and they realize what life is really about. I think he changed a lot of lives," Kimberly Dutter said.

Kimberly Dutter said it was difficult for her to leave for college in Utah when her brother and father moved to Middleton but that she still did what she could to be a part of Kyle Dutter's life.

"I've lived with him pretty much his whole life, so we were pretty close. I mean, we were really close," said Kimberly Dutter. "I want people to remember who he was, not what happened," said Kimberly Dutter.

She said he loved being around people and sharing his life with others.

She said Halloween was a year-round favorite of Kyle's and that, despite being across the country, she and Kyle still carved pumpkins this year over the Internet.

Kimberly Dutter said she never could have imagined that Kyle would be in danger with her father. Kimberly and Kyle's mother said they are working to set up a memorial fund.

The memorial fund the family hopes to set up would raise money for autism research.

The family said it wants Kyle’s name to be remembered for how he touched the lives of others, and not as a victim.

Funeral arrangements have been set for Kyle Dutter. A visitation is scheduled for 4 p.m. to 7 p.m. Monday at Daley Murphy Wisch Funeral Home in Beloit. The funeral will be held at Beloit's St. Jude Catholic Church at 1:30 p.m. Tuesday.

A memorial service for Kyle's father, Ryan Dutter, was held Friday night in Beloit.

Ryan Dutter's mother, Rosemary, said that her son was devoted to Kyle. Rosemary Dutter also said that Ryan's organs were donated when he died. The Ryan Dutter family has set up a memorial fund at the Municipal Credit Union on Cranston Road in Beloit. The money will be used, in part, for autism research.