Which of the following describes crimes of omission?

Crimes of omission refer specifically to situations where an individual fails to perform an act that is legally required. This means that the person has a legal duty to act, and by not taking the necessary action, they commit an offense. Examples of this can include failing to file taxes, neglecting to provide necessary care for a child, or not reporting a crime when legally obligated to do so.

The other options do not accurately capture the essence of crimes of omission. Acting against the law refers to any action that violates legal statutes, while intentionally committing a crime involves a conscious decision to engage in illicit behavior. Using deceptive tactics pertains more to crimes of fraud or dishonesty, rather than the failure to act as required by law. Hence, the correct choice clearly identifies the nature of crimes of omission as a failure to act when there is a legal obligation to do so.