Investigators say the woman and four children who were found dead in an Iowa City home Monday morning were victims of “blunt force trauma.” The chief of police in Iowa City told reporters during a news conference Tuesday afternoon that crime scene evidence shows 42-year-old Steven Sueppel killed his wife and children, then killed himself in a fiery crash on Interstate-80.

Police Chief Samuel Hargadine says Sueppel left voice mail messages and other evidence which indicated he killed his wife and tried unsuccessfully to kill himself and the children by running a car in his closed garage before killing the children, calling 911 to summon police to his home and driving off to commit suicide by crashing his vehicle.

Sueppel had been accused of stealing nearly $560,000 from the Iowa City bank where he worked and was to stand trial in April.

Sueppel killed his wife in the master bedroom, according to police. One child was found dead in a toy room in the basement. The bodies of the others were found in bedrooms in the home. One of the children would have celebrated their sixth birthday today.

Authorities say Sueppel left a handwritten note behind in the kitchen and left several voice mail messages, including messages at the bank where he’d worked and at the Iowa City law firm where his father and brother worked. “He indicated in the voice mail messages that he believed his family was in heaven,” one of the investigators told reporters.