Department of Magical Law Enforcement

The Department of Magical Law Enforcement is the largest department at the Ministry of Magic. Arguably the most important of the various departments, it is a combination of police and justice facilities, and is roughly the equivalent to the Home Office of Muggle Britain or the Department of Justice in the United States. All other departments are answerable to this one, with the exception of the Department of Mysteries.

Divisions
The department is located on the second level of the Ministry of Magic, and includes the following divisions:

Auror Office
Aurors are highly trained, specialist officers who investigate crimes involving the Dark Arts. Aurors are the magical equivalents of Muggle counter-terrorism operatives; Aurors were permitted to use the Unforgivable Curses in combating Death Eaters during the First Wizarding War.

The current head of this office is Harry Potter. Sometime, although not directly, prior to Harry, Gawain Robards was the division head. Before him, the division was headed by Rufus Scrimgeour.

Magical Law Enforcement Patrol/Squad
The Magical Law Enforcement Patrol/Squad is tasked with general law enforcement, like with the Muggle police. In the 1920s it was headed by Bob Ogden, who led a team to Little Hangleton to arrest Marvolo and Morfin Gaunt for crimes against both Muggles and the Ministry, since the Gaunt family had avoided previous attempts at arrest.

Hit Wizards
Hit Wizards comprise a team of highly trained wizards tasked with arresting dangerous criminals. The entry requirements include five O.W.L.s, one of which must be Defence Against the Dark Arts. Members have a personal bed reserved at St Mungo's Hospital for Magical Maladies and Injuries. In 1993, Cornelius Fudge suggested that only Hit Wizards should attempt to capture Sirius Black, an Azkaban escapee then believed to be a highly dangerous criminal.

Improper Use of Magic Office
This office punishes violations of the International Statute of Wizarding Secrecy. This includes underage witches and wizards intentionally using magic, which suggests that this office may be in charge of the Trace, permitting them to monitor the magic used by those under the age of seventeen. Mafalda Hopkirk worked in this office until at least 1998.

Misuse of Muggle Artefacts Office
This office regulates the use of magic on Muggle objects and confiscates those which have been illegally bewitched. One of the laws they enforce is the prohibition on magically altering a Muggle vehicle with the intent to fly it. It was headed by Arthur Weasley until his promotion in 1996.

Office for the Detection and Confiscation of Counterfeit Defensive Spells and Protective Objects
This office was created in 1996 by Minister for Magic, Rufus Scrimgeour, in response to the growing threat of Lord Voldemort and the rise of dangerous or dubious spells and products which claimed to provide protection against the Dark Arts. Arthur Weasley was promoted to head this operation. Its duties involved preventing the trade of fake and/or useless spells, potions and artefacts that appeared during the Second Wizarding War.

Wizengamot Administration Services
An office which undertakes administrative and clerical duties for the Wizengamot. Its function seem analogous to Muggle court registries; this would typically include maintenance of court documents, hearing dates, judges' schedules, and the administration of legal proceedings.

Senior Personnel

 * Justus Pilliwickle — former department head; one of the most notable on the post.
 * Barty Crouch Sr. — former department head, demoted to head of the Department of International Magical Cooperation after his son's exposure as a Death Eater in 1981.
 * Amelia Bones — former department head, killed by Lord Voldemort in the summer of 1996.
 * Pius Thicknesse — former department head, succeeding Amelia Bones; appointed Minister for Magic while under the Imperius Curse following Voldemort's coup in 1997.
 * Yaxley — former department head, succeeding Pius Thicknesse, during the Death Eaters' control of the Ministry of Magic.
 * Hermione Granger — after working with the Department for the Regulation and Control of Magical Creatures, she eventually took a position high up in this department
 * Harry Potter — Head of the Auror Office from 2007.

Notes and references
Département de la justice magique