An arrest is the most intrusive action a police officer may take with respect to a citizen. Once a lawful arrest is established, a number of consequences will occur involving the search for evidence and the recovery of contraband.
As a result of an arrest, evidence can be lawfully seized pursuant to a search of the defendant's person incident to the arrest. Property can also be recovered during an inventory search of the defendant's automobile.
Certain conduct by the police will constitute an arrest, including physical force used by the officer, the drawing of an officer's weapon and the use of hadcuffs by the police.
In addition, excessive force by the police can sometimes constitute an arrest under the Fourth Amendment.
An arrest can be made without a warrant unless it is made in a person's home; here a warrant is normally required.