One evening, Parnell had several drinks and then started to drive home. As he was proceeding down Main Boulevard, an automobile pulled out of a side street to his right. Parnell's car struck this automobile broadside. The driver of the other car was killed as a result of the collision. A breath analysis test administered after the accident showed that Parnell satisfied the legal definition of intoxication. If Parnell is prosecuted for manslaughter, his best chance for acquittal would be based on an argument that 
the other driver was contributorily negligent. the collision would have occurred even if Parnell had not been intoxicated. because of his intoxication he lacked the mens rea needed for manslaughter. driving while intoxicated requires no mens rea and so cannot be the basis for misdemeanor manslaughter.