If the officer realizes the detained person is not the suspect after stopping, continuing detention is illegal.

• A. It is allowed
• B. It is allowed if the officer has extra evidence
• C. It is illegal to extend detention after realizing the person is not the suspect
• D. It is permissible to detain for further questioning

Answer: (C)

Detention during a stop must be tied to a specific and ongoing basis for suspicion, and it should end as soon as that basis no longer exists. When it becomes clear that the person stopped is not the suspect, the justification for keeping them detained disappears, so continuing the detention would be an unlawful seizure under constitutional protections. The only way to lawfully extend detention would be to establish a new, independent basis—such as probable cause to arrest for another crime or obtaining the person’s voluntary consent—before allowing any further detention or questioning.

In practice, this means you should release the person once you know they aren’t the suspect unless some new lawful ground arises. Detaining for further questioning would require a fresh, valid basis; simply having extra information does not automatically justify extending detention if there is no independent cause to hold.