A law enforcement officer must release an arrested subject when which of the following occurs?

The correct answer is based on the legal principle that a law enforcement officer is required to have probable cause to make an arrest. Probable cause is the reasonable belief that a person has committed a crime or is in the process of committing one. If the probable cause supporting the arrest dissolves, the officer must release the arrested individual. This situation can occur if new evidence emerges that contradicts the basis for the original probable cause or if the time that has elapsed since the arrest makes it unreasonable to continue holding the individual without formal charges.

In the context of this question, the other options do not introduce circumstances that necessarily require the release of an arrested individual. For example, the filing of a false arrest lawsuit or claims related to the Fourth Amendment may present legal ramifications or challenges, but they do not, in themselves, invalidate the probable cause necessary for the ongoing detention of the arrestee. Thus, if the probable cause dissipates, the officer must act to release the individual, making the response about the dissolution of probable cause the only appropriate answer in this context.