Which of the following is NOT a valid reason for conducting a stop and frisk?

A traffic violation is not necessarily a valid reason for conducting a stop and frisk. While a traffic violation may justify a traffic stop, it does not inherently provide the officer with the reasonable suspicion necessary to conduct a frisk for weapons or contraband. The concept of stop and frisk, established by the Supreme Court in Terry v. Ohio, requires that an officer must have specific and articulable facts that suggest a person is involved in criminal activity and may be armed and dangerous.

In contrast, witnessing suspicious behavior, detecting a strong aroma of illegal substances, or encountering someone whose identity is unknown can all contribute to a reasonable suspicion that justifies a stop and frisk. These situations imply potential criminal activity, allowing law enforcement to ensure their safety while investigating further.