Voiceprint, a visual representation of a person's voice used for purposes of identification. A voiceprint is made with a sound spectrograph, a device used to analyze complex sound waves. The voiceprint appears as a pattern of tracings that indicate the moment-by-moment distribution and relative strengths of a voice's component frequencies. The voiceprints of different people speaking the same words generally show patterns unique to each speaker. Unlike fingerprints, however, voiceprints made at different times (of the same person speaking the same words) may show some variation. Voiceprints were first used as evidence in a court of law in 1966.
Such famous artworks as 'Mona Lisa' and 'The Scream' have been stolen and returned; some have never been found. Art burglars either keep the artwork for themselves, or try to ransom it back to the original owner. Learn about 7 notorious art thefts.
The U.S. was quick to denounce 9/11 as an act of terrorism. Drawing the line between mass murder and terrorism isn't always that straightforward though.