DES MOINES, Iowa (AP) — A mother and her four children found dead in their Iowa City home were beaten to death, apparently by the father, authorities said Wednesday after autopsy results were released.

Sheryl Sueppel, 42, and the children died of injuries to their upper torsos and heads, Iowa City police said. Two baseball bats found in the home appear to have been used, police said.

Police believe the woman's husband, former bank executive Steven Sueppel, killed her and the children Sunday night or Monday. He had been charged with embezzlement, and his body was found in the wreckage of a car crash Monday.

Investigators say they believe he killed his wife, then tried to kill himself and the children by asphyxiating them with carbon monoxide in the garage. When that failed, he killed the children one by one.

Before he died, Steven Sueppel left a hand-written four-page note in which he detailed the killings. The note was left in the kitchen and apparently was written for surviving family members.