Poison is an almost invisible form of death and is often interpreted as a heart attack or underlying health issue. But when foul play is suspected, toxicologists must look for hidden clues in blood and tissue to bring these murders to light.

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.

There’s an old saying that a burden shared is a burden halved. But when people team up to commit murder, the weight of their guilt remains just as heavy. Investigators must rely on forensic science to capture partners in crime.

What does it take to prove murder if the victim cannot be found? Forensic investigators must go to great lengths to catch the killer when the victim is only presumed dead.

Poisoners are the most dangerous culprits in the crime world: smart assassins. They rely on their devious stealth and must put their victims at ease to earn their trust. And, usually, they don’t stop at just one victim.

Forensic psychologists delve into the minds of serial killers, explaining why, most often, they can be a friendly neighbor or a tenacious co-worker – the ones who hide their darkness better than anyone else.

The Texas Rangers were established in the 1800s to protect settlers from Native Americans. That role has evolved greatly over time to keep up with a changing society. Today, their job includes solving murders with advanced forensics labs.

Sometimes, seemingly small and insignificant clues – three hairs, microscopic fibers, a paint chip – become a victim’s silent witness and help solve even the most baffling of cases.

Sometimes, cooperation from people who are not associated with a crime in any way is the only link between a criminal and the clues left behind for forensic experts. This episode examines cases in which good Samaritans help solve puzzling crimes.

Even ordinary objects, when used to kill, carry enough evidence for forensic scientists to piece together the most complicated murders. In this episode, criminals are brought to justice with evidence found on mundane, household objects.

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.

Often, a killer will build the victim’s trust before he or she attacks. In this episode, New Mexico police search for a missing teenager who disappeared from a local skating rink. Authorities suspect the two friends she was last seen with.

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.

Solutions to atrocious crimes can hinge on the smallest of clues. Even with advanced technology, vision remains an important tool. Forensic investigators must train their eyes to find the full story of a murder written in a single scrap of evidence.