A situation when law officers decided to pursue or drop charges.
As an elected or appointed official, the prosecutor is the most powerful official in the criminal justice system. Prosecutors exercise unfettered discretion, deciding who to charge with a crime, what charges to file, when to drop the charges, whether or not to plea bargain, and how to allocate prosecutorial resources. In jurisdictions where the death penalty is in force, the prosecutor literally decides who should live and who should die by virtue of the charging decision.
When a person is arrested, they may be guilty but criminal charges may not always be pursued.
In lighter cases, people who are arrested may be released even when they are likely guilty. For example, a criminal’s car is identified near a breaking-and-entering crime. A witness offers a weak description that could match the criminal’s description. A security camera captures an image only of the the lower leg and shoe that matches the description of the criminal, but not other images are captured. Breaking and entering has occurred, but nothing is identified as stolen.
The case of Henry Louis Gates being released after arrest is also an example of Prosecutorial Discretion. When police release an offender, the release is not an admission of false arrest. The police could arrest again later, or they could decide that the case is not strong enough against the offender, or they could have compassion for the offender under certain circumstances.
For example a solicitor is warned not to ignore ‘No Solicitor’ signs; or a speeder is given a warning ticket, instead of an actual traffic ticket.