Arrest is the apprehending or detaining of a person in order to answer for an alleged or suspected crime. The U.S. Constitution's Fourth Amendment authorizes arrests only if the police have "probable cause" to believe that a crime was committed and that the suspect did it.
A citizen is allowed to make an arrest in certain instances, as determined by state laws, which vary by state. Making a citizen's arrest maliciously or without reasonable basis in belief could lead to civil or criminal penalties. It is a violation of a suspect's civil rights to use excessive force, to torture, to hold in unsafe or cruel conditions or to invent a reason to arrest for the ulterior motive of settling a private score.
An arresting officer may be defined narrowly as the officer who takes physical control of and arrests a person, or more broadly as any law enforcement official who exercises control over a suspect, regardless of whether that officer is the one who actually assumes physical control over that suspect. The following is an example of a local law governing arresting officers:
"1.08. 070 Arresting officer defined.
For the purpose of this chapter, the term "arresting officer" means any police officer of the city and any other employee of the city whose duty it is to enforce the provisions of this code who is authorized by the city manager to use the citation procedure established by said sections in the performance of his enforcement duties."