A peace officer may make a warrantless arrest if they have probable cause to believe what?

• A. They have probable cause to believe a felony occurred
• B. They witnessed the offense
• C. They have a warrant
• D. They receive a citizen's complaint

Answer: (A)

In California, the authority to make a warrantless arrest rests on probable cause to believe a felony has occurred. If a peace officer has that probable cause, they can arrest on the spot without a warrant, even if they didn’t personally witness the crime. This standard is what makes the option describing probable cause to believe a felony occurred the best choice, because it directly matches the rule for felonies.

The other ideas don’t fit as well: having a warrant means the arrest isn’t warrantless; a citizen’s complaint alone doesn’t establish probable cause; and while witnessing the offense would justify arrest in many cases, the key requirement the question focuses on is proving probable cause that a felony occurred.