My guess is he will be charged with vehicular homicide. If he had not fled the scene he may have avoided the charge.
VEHICULAR HOMICIDE LAWS IN IOWA
An individual commits vehicular homicide when:
(1) Unintentionally causes death of another; by
(2) Operating a motor vehicle while intoxicated.
Penalties:
Mandatory 25 years imprisonment; Judge may not give probation or defer judgment. Prison sentence must be imposed. If convicted the Judge has no choice but to send you to prison. Furthermore bail is not available pending appeal or while awaiting sentencing.
Fine of up to $10,000 but not less than $1,000 plus 32% surcharge, court costs, $125 Law Enforcement Initiative Surcharge and $10 DARE surcharge;
Mandatory $150,000 restitution to victim's estate;
Substance abuse evaluation and treatment if recommended;
Drinking drivers course; and
Mandatory 6 year license suspension.
Vehicular Homicide can be charged in only two instances:
if the person was impaired (doesn't necessarily have to be above the limit, but must be impaired)
Or if the person was doing something very reckless (think street racing). Just a regular, sober hit and run wouldn't rise to that level.
Frankly, unless there is some very good evidence that he was drinking before this happened, Vehicular homicide is out of the question, IMO. Even charging him with it is pretty reckless on behalf of a prosecutor because it would such a tough case to prove, and if you don't win, he basically gets off scott-free.
My guess is that there will be as many charges as they can reasonably throw at him thrown at him, but one of those won't be vehicular homicide.