California residents who are facing criminal charges may also face a question about their state of mind at the time the incident allegedly happened. "Mens rea" is a Latin term that means "guilty mind" and that in a legal sense refers to whether or not a person intentionally committed an act.
One distinction is civil or criminal negligence. Another is whether a person makes a mistake in fact or a mistake in law. A person might think an illegal substance is something else and sell it to another person. This is a mistake in fact that they will probably not face prosecution for. However, if the person knows what the substance is but not that it is illegal, they may be culpable. For strict liability laws, which often deal with minors, intent is not considered important. This is why a person can be convicted for supplying alcohol to a minor even if the person did not realize that they were serving someone who was underage.
Whether or not a person "knowingly" committed a crime, such as carrying drugs, is also an issue. A crime committed "maliciously" or "willfully" may increase the penalties. Like "knowingly," "specific intent" refers to whether or not a person intended to commit a crime. Motive is one important reason for establishing state of mind. Without motive, a jury may have reasonable doubt.
One of these points about state of mind will often be used by a criminal defense attorney representing a client who has been charged. For example, a person might be facing drug charges, but the attorney may argue that the defendant was unaware of the presence of the drugs and that they belonged to someone else.