Journey into the dark recesses and calculated madness present only in our worst nightmares; and in the minds of serial killers, such as Richard Chase - The Vampire Killer of Sacramento, Mike DeBardeleben - The Mall Passer, and John Wayne Gacy - The Killer Clown, to name just a few. Renowned FBI profiler Robert Ressler can reveal unseen clues about a killer simply by learning details about the crime. Investigative profiling discloses a killer's hidden motives.

Forensic photographers are amongst the first people at a crime scene, capturing vital clues on film. What do the cameras capture that can't be seen first-hand and who are the men and women who analyse these camera clues?

With DNA analysis just a few microscopic cells found at a crime scene can be used to convict a killer. Forensic scientists can analyze droplets of blood, hair fiber, or a piece of chewed gum to determine the identity of a victim or killer -- or to prove innocence.

Forensic Entomology: Bug have been around for millions of years. Their habits surrounding death can tell these experts when the victim died.

Forensic Sculpting: These experts can take nothing more than their knowledge, clay, and a skull and bring the victim to life. Once nameless victims can now have a name.

Missing Person: In America nearly 1.8 million people are reported missing each year, factor in the world and that number triples. Using computer databases and other means victims are found, laid to rest…or never seen again.

Identifying Burned Remains: Murder is hard to prove with no body, when the victim has been burned it is even more difficult. Fire does more than destroy evidence . . . it can keep the secrets you don’t want anyone to know.

Explosives Investigations: A woman opens a box which explodes killing her. Soon to follow are five other bombs just as deadly as the first. This soon turns into a massive investigation leaving the experts to sift though the evidence.

Fingerprinting: The backbone to forensic science, the fingerprint is a very effective way to identify victims and criminals. Not only are fingerprints used but also palm prints and foot prints. Data entered into massive databases make identifying people easy…when there is a hit.

Handwriting Analysis: Every pass of the pencil leaves a little of ourselves behind. Taking the time to evaluate documents can tell the difference between suicide and murder.

Black Boxes: A plane plunges toward the ground and upon impact little remains. The only possible survivor is the flight data recorder. This little black box could hold the answers to the last terrifying minutes.

Forensics in the O.J. Simpson Murder Trial: The verdict is in Not Guilty of murder. O.J. Simpson emerges a free man. What was the evidence and could it be trusted? These experts break down the evidence could and could not tell us.

Ballistics: A body with a gunshot wound to the head, the gun is next to the body. Was it suicide or murder? Every part of the gun can be analyzed for the correct answer.

Time of death is an important consideration in an investigation but when a killer destroys the body, even the best medical examiner would be at a loss about how to calculate death's time frame. Forensics has its own techniques for solving these crimes.

Accidental deaths, suicides, disappearances and fires: they’re an everyday part of an insurance investigator’s job. But these cases shouldn’t be taken at face value. Forensics has become a vital tool in exposing insurance fraud.

Drowning deaths often look like accidents and over time water can destroy the few clues the killer may have left behind. Investigators must turn to forensic science to solve homicides in which the victims were found in bodies of water.

When theft is committed, something valuable is stolen. But when a criminal needs a new identity, theft becomes lethal.

Photography has long been a fundamental tool in homicide investigations. A single image can hold enough information to identify a suspect and preserve vital clues long after a witness’s memory fades.

When murderers hide or destroy the remains of their victims, forensic scientists must reconstruct the scenes and prove murder for an absent witness.

Coroners play a vital role in piecing together the final moments of someone’s life. Los Angeles County coroner Julie Wilson provides an in-depth look into the science of death, as well as the techniques and methodology used by coroner investigators.

A house fire in California turns into a murder investigation when authorities discover that the victim’s best friend and personal manager had recently cleaned out her bank account.

Often, criminals misuse the trust they’ve built with their victims to commit heinous misdeeds. A family discovers the mummified remains of a pregnant woman; a nurse notices an unusually high number of deaths in an ICU unit and suspects foul play.

Insurance torchings, mob burnouts and arson murders: these crimes are designed to take all clues with them. But a case can be built from ashes. Arson investigators do everything from gathering physical evidence to mounting undercover operations.

Contract killings allow someone to establish the perfect alibi. By hiring someone else to do his or her dirty work, a person can deflect guilt or twist the truth. Forensics is changing that, leading investigators to the employers of killers.

A murdered woman is found stuffed in the boot of her car, and a routine investigation reveals a wife may not have abandoned her family on purpose. When everyday substances reveal hidden clues that break a homicide case, those substances become the elements of murder.