WHEN IS AN ARREST WITHOUT WARRANT LAWFUL?
> A peace officer or private person may arrest without warrant:
1. When, in his presence, the person to be arrested has committed, is actually committing, or is attempting to commit an offense;
2. 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
3. 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.
4. In hot pursuit
A POLICE OFFICER WAS CHASING A PERSON WHO HAD JUST COMMITTED AN OFFENSE. THE PERSON WENT INSIDE A HOUSE, SO THE POLICE OFFICER FOLLOWED. INSIDE THE HOUSE, THE POLICE OFFICER SAW DRUGS LYING AROUND. CAN HE CONFISCATE THE DRUGS AND USE THEM AS EVIDENCE?
> Yes. The plain view doctrine is applicable to this case because there was a valid prior intrusion. The police officer inadvertently discovered the evidence, he had a right to be there, and the evidence was immediately apparent.
WHAT IF THE OFFICER MERELY PEEKS THROUGH THE WINDOW OF THE HOUSE AND SEES THE DRUGS, CAN HE CONFISCATE THEM AND USE THEM AS EVIDENCE?
> He can confiscate them, without prejudice though to his liability for violation of domicile.
> He cannot use them as evidence because the seizure cannot be justified under the plain view doctrine, there being no previous valid intrusion.
WHAT IS THE EFFECT IF A WARRANTLESS ARREST IS ILLEGAL?
> It doesn't render void all other proceedings, including those leading to the conviction of the accused nor can the state deprived of its right to convict the guilty when all the facts of record point
to his culpability
Sec. 5. Arrest without warrant; when lawful. – A peace officer or a private person 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 paragraphs (a) and (b) above, the person arrested without a warrant shall be forthwith delivered to the nearest police station or jail and shall be proceeded against in accordance with section 7 of Rule 112.
