When a crime is committed, prosecutors have one goal: prove, beyond a reasonable doubt, that the defendant is guilty of a criminal act. Though courtroom dramas and police procedural shows make this look quite simple, life isn’t very much like TV; criminal defense lawyers and legal defense teams work their hardest to defend their clients and push the reasonable doubt to the best of their ability.

Regardless of which side is “right,” there are rules to follow; that’s where the four elements of a crime come in. An element of a crime is one of a set of facts that must all be proven to convict a defendant of a crime. Prosecutors are tasked with providing evidence that is credible and sufficient to prove (beyond a reasonable doubt, of course) that the defendant committed each element of the particular crime charged. Let’s break them down.

Mental state (mens rea): Mens rea refers to the crime’s mental elements, specifically those associated with the defendant’s intent; the criminal act must be voluntary or purposeful. Mens rea is almost always a necessary component in order to prove that a criminal act has been committed.

Conduct (actus reus): Actus reus is required for all crimes. That is, a criminal act (or unlawful omission of act) must have occurred. Basically, this means you can’t be punished for thinking criminal thoughts if you’ve never acted on them.

Concurrence: Mens rea and actus reus must occur at the same time; the criminal intent must precede or exist at the same moment the criminal act occurs. For criminal liability to occur, there must be either overt and voluntary action.

Causation: Many crimes include an element where actual harm must occur. For example, homicide requires a killing, and aggravated battery requires serious bodily injury — without those respective outcomes, the crimes could not have actually been committed.

From DUI law to hard-hitting criminal offenses, legal defense teams and criminal attorneys will be there to inform defendants of their rights and provide counsel. Whether you’re defending yourself from a crime or are seeking to convict someone else of committing one, you are always entitled to legal representation: the Sixth Amendment guarantees it.