Sometimes those closest to a victim can be the most dangerous. Beneath a layer of trust can lurk a deadly obsession. In these cases, authorities employ an arsenal of forensic techniques to uncover the twisted path of lies that leads to 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.

Marriage is one of the tightest bonds two people can have, until lies and deceit drive one of them to kill. In this episode, forensic experts are employed to link a woman’s husband to her violent murder and uncover a murder disguised as an accident.

Sometimes the faintest fingerprint or tire track is all investigators need to solve even the most brutal of crimes. When a woman’s body is discovered in a field, detectives employ a rarely used technique to bring her killer to justice.

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.

A killer will often try to disguise the victim’s body in an attempt to the hide the actual cause of death; however, forensics cannot be fooled. In this episode, authorities use reverse DNA testing to identify remains and solve an old crime.

When money is the motive, there is no limit to what a killer will do to get away with their fortune. When officers find the dismembered remains of a young man, they also discover his girlfriend recently took out an insurance policy on the deceased.

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.

The most sacred of vows are sometimes not enough to stop a serious desire. In this episode, a nurse suspects a patient’s husband of attempted murder by poisoning and a man stages his depressed wife’s murder as a suicide.

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.

When the amount of money is substantial, a person can be motivated to do terrible things to someone they love. Police discover that a large life insurance policy was motive for a man’s murder. A woman hires help to cover up her husband’s death.

Murdering a child is perhaps the most heinous of crimes. But no matter how defenseless a killer believes a young child to be, there is no hiding from the clues left behind.

Forensic science has advanced so much that even the oldest remains still share the clues necessary to convict a killer. Investigators use DNA to solve a murder case from 1980.

Blood can be the most telling evidence of a murder and often it is the only thing investigators have to link a killer to his or her victim. Forensic scientists and medical examiners look at blood spatter patterns to determine how someone was killed.

Whether it is a fingerprint or a single bullet, sometimes it is the smallest piece of evidence that is needed to crack the biggest cases. In this episode, detectives use an ingenious technique to find the bullet that killed an elderly man.

When an unexpected crime occurs with no eyewitnesses, very few clues and the killers on the run, authorities must rely on forensic science to discover the fatal twist in these cases.

Murderers will go to great lengths to keep their crimes concealed, but forensic evidence is impossible to cover up. In this episode, authorities rush to identify bodies found in drum barrels and locate several missing women linked to the killer.