Usually when a crime is strict liability, it is a public welfare offense. It is usually attached to crimes that the legislature has labeled as criminal. They need to be strict liability because there is a public welfare benefit from labeling it as so. Staples v. united states (strict liability case: facts: guy had an ar-15 that was modified to be an automatic. The guy said that the rifle had never been shot automatically in his possession. He alleged that his ignorance of any automatic capabilities should shield him from criminal liability: rule: this is a public welfare crime that is strict liability. Thus, no mens rea is needed for criminal liability. The fact that he owned this gun means that he is strictly liable. Garnett v. state (strict liability case: facts: d was a mentally delayed man. At the time of the incident, he was twenty years old.