Kevin L. Amde, 45, was found Saturday tied to his two sons, 3-year-old Tesla E. Amde and 6-year-old Davinci Amde, on a beach in Pleasant Prairie, said Brian J. Wagner, the village's police chief.
The three were last seen on May 6, when the father picked Davinci up from school in Chicago, he said. Veronica Amde, Kevin Amde's wife and the mother of the two children, reported them missing on May 11.
The Kenosha County Medical Examiner's Office said the amount of time the three were believed to have be in the water was consistent with the date they were reported missing.
But no official cause of death has been released, and there was no evidence of trauma on any of them, Wagner said.
"We consider these deaths to be very suspicious and this case is being handled by law enforcement as a homicide," he said.
Wagner said the bodies were tied together with nylon rope, either though belt loops or wrapped around one of the child's body.
Also tied to the bodies were two nylon book bags, he said, and inside each bag were two plastic bags filled with sand.
"One of the children also had pants pockets filled with sand, which had been zipped closed," he said. This added 48 pounds of weight to the bodies, he said.
Sgt. Stephanie Stuart of the Chicago Police Department (search) said Kevin Amde often took his children on trips without telling his wife. They would visit museums in Chicago, go fishing or come to Wisconsin, where they had family in Racine.
Stuart said there was no indication that the couple were having problems, and Wagner said he had no knowledge of Amde having mental health or criminal problems.