This refers to DHS authority to decide whether or not to enforce immigration laws against a noncitizen. When deciding so, the DHS has a range of options which may include:
Whether a noncitizen will be the target of an investigation;
Whether to oppose permanent or temporary immigration benefits sought by a noncitizen in immigration court;
Whether to move to terminate or to administratively close proceedings as well as many more options available to the DHS.
There are several factors that ice should consider in determining whether to exercise prosecutorial discretion:
Length of residence in the United States;
Immigration history and several other factors that are taken into consideration when deciding to exercise prosecutorial discretion.
Prosecutorial discretion is a matter of policy, not law — the discretion that any law enforcement agency, be it a prosecutor’s office or Department of Homeland Security, has to decide why, when and how to enforce the law.
In the field of immigration law, prosecutorial discretion is defined as the authority that DHS has to decline to initiate or close removal proceedings, choose to forego existing removal orders and decide to not contest motions to reopen removal and terminate removal proceedings.