Arrest is the taking of a person into custody in order that he may be bound to answer for the commission of an offense.
It is made either by an actual restraint of a person to be arrested, or by his submission to the custody of the person making the arrest. And it may be made on any day and at any time of the day or night.
But no violence or unnecessary force shall be used in making an arrest. And the person arrested shall not be subject to a greater restraint than is necessary for his detention.
Before an arrest could be made, however, there must be a valid warrant issued to this effect by a judge. Otherwise, the arrest would be deemed unlawful.
There are, nonetheless, cases when arrest may be lawfully made even in the absence of a warrant. Thus, one may, without a warrant, arrest a person:
(a) When, in his presence, the person to be arrested has committed, is actually committing, or is attempting to commit an offense;
(b) When an offense has just been committed and he has probable cause to believe based on personal knowledge of facts or circumstances that the person to be arrested has committed it; and,
(c) When the person to be arrested is a prisoner who has escaped from a penal establishment or place where he is serving final judgment or is temporarily confined while his case is pending, or has escaped while being transferred from one confinement to another.
In cases falling under items (a) and (b), the person arrested without a warrant shall be immediately delivered to the nearest police station or jail and shall undergo inquest proceedings.
An inquest is a summary inquiry conducted by a public prosecutor for the purpose of determining whether the warrantless arrest of a person was based on probable cause.
In all those cases when arrest may be lawfully made without a warrant, not only a peace officer, but also a private person may make an arrest. But, unlike a peace officer, a private person has no right to break into any building or enclosure.
When a private person is making an arrest, he is duty-bound to inform the person to be arrested of the intention to arrest him and the cause of the arrest.
But those duties may be dispensed with when the person to be arrested is either engaged in the commission of an offense, is pursued immediately after its commission, or has escaped, flees, or forcibly resists before the person making the arrest has the opportunity to so inform him, or when the giving of such information will imperil the arrest.
The right of a private person to make an arrest is known as “Citizen’s Arrest.”
[References: Rules 112 and 113 of the Rules of Court, The Revised Rules on Criminal Procedure [2003 Edition] by Dean Ernesto L. Pineda, and Imelda S. Enriquez vs. Judge Olegario R. Sarmiento, Jr., A.M. No. RTJ-06-2011 (formerly OCA I.P.I. No. 04-2083-RTJ), August 7, 2006]