What term describes an individual who is equally responsible for an offense?

The term that describes an individual who is equally responsible for an offense is an accomplice. An accomplice is someone who assists, supports, or participates in the commission of a crime, sharing the culpability of that crime with the principal offender. This means that an accomplice can be charged and held accountable for their role in the offense as if they had committed the crime themselves.

In the context of criminal law, accomplices can help in various ways, such as planning the crime, providing necessary tools, or aiding in the escape after the crime has been committed. This shared responsibility emphasizes the collaborative nature of criminal activities, where multiple individuals play roles that contribute to the commission of an offense.