Abstract
Recently, the causes of mechanical accidents become more complicated and technological. But Japanese historical criminal low, e.g. negligent homicide can be still applicable only to a simple and human-error-typed case. On the other hands, public prosecutors need a legal story to charge some engineers, not to clarify an engineering truth. Therefore, justices sometimes did not explain any engineering causes of the accident although the court had exclusively investigated the accident's evidences for several years. Engineers except the persons concerned, however, want to know the entire cause of the accident, and improve their own design methods as soon as possible. So far, engineering and law could not work together toward investigating the cause of the accident. In near future, the civil low will relieve a victim at soon; and the criminal low should have a plea bargaining with engineers to get the accident's evidences against the complicated and technological case.
