Profiling has played a major role in criminal investigations. When traditional investigative methods go nowhere, profilers look at evidence to form a theoretical description as to who the killer might be.
Minuscule evidence that can't be seen with the naked eye, is a crucial investigative tool in modern forensic science. It catches killers who think they've done everything to cover their tracks.
Modern fire investigation was born during 1990's horrific Lime St. Fire in Jacksonville. It then fully came-of-age in 2007 when science brought a teenage arsonist to justice in Glassboro, NJ.
Bloodstain analysis is a key factor in investigating any violent crime, but it didn't gain a foothold until the 1950s when the infamous Sam Sheppard case made headlines around the world.