Iowa City police said they were all but certain that the body in the van was that of the husband, Steven Sueppel. A lockdown for city schools and an alert for the University of Iowa were lifted after the body was found.
Police Sgt. Troy Kelsay wouldn't release the names of the victims, but he confirmed they were Sueppel's wife and children, ages 3, 5, 7 and 10. Police said they were found in the unlocked house Monday morning.
Dispatchers got a call at 6:31 a.m. saying officers needed to get to the address immediately. The caller then hung up, police said. According to a report in the Iowa City Press-Citizen, the call was placed from a cell phone.
Initial alerts said there had been a shooting at the home, but Kelsay said further investigation shows the deaths could have been the result of some other trauma. Autopsies for the six bodies were scheduled for Thursday.
"I'm not certain that a firearm was ever involved. Nobody reported hearing any shots fired," Kelsay said.
The family's van crashed and caught fire on Interstate 80 about nine miles from the home. No other vehicles were involved.
"It's not possible to do an ID short of an autopsy. The fire was that intense," Kelsay said.
He added, however, that "if I was a betting man I would comfortable betting a fair chunk of money" that the body was Sueppel's.
The slayings do not appear to be random, Kelsay said.
"It's certainly a tragedy, whoever is responsible for it," he said. "... This does not appear to be a random crime. It appears that possibly it is the work of Steven Sueppel."
Court records show that Sueppel was indicted last month on charges of stealing about $560,000 from Hills Bank and Trust in Johnson County, where he was vice president and controller.
Sueppel, 42, pleaded not guilty to embezzlement and money laundering in U.S. District Court and was released on a $250,000 personal bond. The government was also seeking the forfeiture of the money he was accused of stealing.
His trial was scheduled for April 21.
Sueppel's attorney in that case, Leon Spies, said he had heard of the deaths.
"I had great affection for Steve and his family. This is an unimaginable professional and personal tragedy for a lot of people," he said.
The bank issued a statement expressing "our heartfelt sadness for the events that occurred earlier today," and said officials' thoughts and prayers were with the family.
Roberta Caris, who lives in Sueppel's neighborhood, said that her two daughters were friends with the family's children and that "they were great people and they were involved with their kids." She said she knew that Steven Sueppel had been "distraught" over the federal indictment, "but there was no indication that this would happen."
Three young girls who live in the suburban development and knew the family wrote chalk messages on the sidewalk in the area that said, "We are going to miss you guys," and "I wish that this day never came."