The New Detectives

Often, the eyewitnesses of a crime are also the main suspects. They're able to manipulate the truth to throw off the authorities. When a murder is committed and deceit clouds the evidence, investigators turn to forensics to uncover the truth, expose a murderous lie and capture the killer.

A simple clue can provide the missing link by placing a suspect at the scene of the crime.

Bombers, snipers, spree killers: some people don't care who they kill, they just want to hurt innocent people. These killers are the hardest to catch because they have no connection with their victims, who are just in the wrong place at the wrong time. But even random bloodshed leaves traces at the scene that can direct an investigation and stop the killer before he can strike again.

Approximately 1.8 million Americans are reported missing each year. Some are runaways who find their way home, but others simply disappear. When foul play is suspected, investigators turn to forensics to find the missing.

Time of death is an important consideration in a murder investigation but when a killer freezes, burns or even grinds his victim, even the most expert medical examiner would be at a loss about how to calculate a time frame. Forensics has its own techniques to solving these grisly crimes.

Police use trace evidence and paint analysis to track a killer of gay prostitutes; a husband is linked to his estranged wife's murder by saliva and ink found at the scene.

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.

Some people do get away with murder, at least for a while.

At the scene of a murder, sometimes the only clues to the killer come from the victim.

The rape and murder of Janet Baxter, the ransom kidnapping and murder of Michael Kinney, and the murder of James Bradley Wren are examined.

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.

Some dogs have been trained by law enforcement to sniff out corpses.