From the courtroom to the living room (thanks to the hit television series CSI), forensic science is king. Expertise on fingerprints, ballistics and bite mark analysis are routinely called on to solve the most difficult criminal cases — and to put the guilty behind bars. But how reliable is the science behind forensics? A FRONTLINE investigation finds serious flaws in some of the best-known tools of forensic science and wide inconsistencies in how forensic evidence is presented in the courtroom. From the sensational murder trial of Casey Anthony and the FBI's botched investigation of the Madrid terrorist bombing to capital cases in rural Mississippi, FRONTLINE documents how a field with few uniform standards and unproven science can undermine the search for justice. As part of the investigative series Post Mortem, Correspondent Lowell Bergman reports in a joint investigation with ProPublica and the Investigative Reporting Program at UC Berkeley.