In which situation must an officer stop questioning?

An officer must stop questioning a suspect when the suspect requests a lawyer. This is rooted in the rights granted by the Miranda warning, which protects an individual's Fifth Amendment right against self-incrimination. When a suspect invokes their right to counsel, the officer is legally obligated to cease any further questioning until the suspect's attorney is present. This safeguard ensures that the suspect has access to legal representation, which is essential for protecting their rights during an interrogation.

The other scenarios do not warrant a cessation of questioning. An officer being tired does not impact the suspect's rights or the legal obligations of the officer. Insufficient evidence does not necessarily correlate with the need to stop questioning, as an officer may continue to gather information regardless of the current evidence status unless a legal right is invoked. Lastly, there is no legal timeframe that restricts questioning to a specific duration, such as two hours; the presence or absence of a lawyer is the decisive factor in whether questioning can continue.