What is necessary for a defendant's arrest according to the law?

For an arrest to be lawful, there must be probable cause. This means that law enforcement officers have a reasonable belief, based on the available facts and circumstances, that a crime has been committed and that the person being arrested is involved in that crime. Probable cause is a foundational principle that protects individuals from unreasonable seizures and ensures that arrests are justified based on reliable information rather than mere suspicion or arbitrary actions.

While a warrant and evidence of guilt can play roles in the arrest process, probable cause is the critical element that must be established for an arrest to take place. A warrant is a legal document that authorizes law enforcement to make an arrest, but it cannot be issued without probable cause. Evidence of guilt refers to what may be used in a trial to show someone committed a crime but is not a direct requirement for arrest itself. A subpoena is a legal order requiring someone to appear in court or produce evidence and is not related to the act of making an arrest.