Feel like I've seen this not watching film noir but somehow seen excerpts or ............ ? Someone under suspicion of having committed a crime is being questioned at the station and has a bright light shined on their face and the questioner sits behind the light? I guess the idea is the questioner can see every facial expression very clearly and make a better decision about whether they're lying or what they're feeling as they answer questions? But is this actually a thing in old movies? Does it reflect something real police did?