
Eagle-eyed technical experts prove there is no such thing as a perfect crime as they assemble the pieces every criminal leaves behind. Dramatic crime re-creations and, sometimes, part of the investigations are a staple of the series. Some of the re-creations include alternate versions of the crimes, which are disproved by science. The show's episodes follow each case from the initial investigation until it reaches its legal resolution.
In a wealthy area of Philadelphia, police are called to the scene of what seems like a regular accidental drowning; the investigation begins to focus on one person who has many reasons to want the victim dead.
Two women are murdered in the same town and police fear a serial killer is on the loose, further investigation finds that they were both close to the same man.
A young woman is found dead on a golf course in the Bahamas; the grass on that course is so distinctive that it had evidentiary value; the evidence leads police to two suspects; each blamed the other, and they have to find out who the killer is.
A teenager goes missing after an evening of horseback riding; her body is found a month later, three miles from her home; the killer unknowingly leaves a trace of evidence behind, tiny but unmistakable clues that pointed to him and him alone.