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The first dispatch call to Maquoketa Caves State Park after three family members were killed while camping has been released.

Tyler and Sarah Schmidt and their 6-year-old daughter Lula were all found dead in their tent. Arlo Schmidt, 9, survived.

Police said the suspect, 23-year-old Anthony Sherwin, was at the park with his parents.

Police say Sherwin had no contact with the people he killed before the shooting, police said.

The Iowa Division of Criminal Investigation said Sherwin's parents are cooperating with the investigation. They are from La Vista, Nebraska, an Omaha suburb. Sherwin lived with them.

DCI said they are working to find out why this happened.

"Sometimes, motives aren't revealed, so to say, or discovered. And at this time, we don't have any information that would lead us to a motive in this," Iowa DCI Assistant Director Mitch Mortvedt said.

Police in La Vista did go to his house for a welfare check Friday, but his parents were not home.

Sherwin's mother, Cecilia Sherwin, told the Omaha World-Herald that there was no sign her son would have been capable of something like this. She told the newspaper the family refuses to "believe the news."

Cecilia Sherwin said the family was camping at the park Friday morning when she heard yelling and two gunshots. A young boy ran up to the Sherwins' campsite asking for help. He told her a man wearing black had shot his family.

Cecilia Sherwin said her son was wearing green — not black.

She also said the family was legally traveling with a gun in a secure container.

Cecilia Sherwin said she told investigators her son was missing and they feared he had been killed by the man the young boy described.

Anthony Sherwin was later found dead. Investigators said he shot himself.

While she said she doesn't think her son was capable of this kind of violence, she told the World-Herald: "I didn't think we had any tears left but we still find ourselves breaking down and care deeply for the little boy and the loss of his family."

Iowa DCI said autopsies on the Schmidt family and Anthony Sherwin should be complete in the next few days.

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