Fire and Ashes, the latest Angela Richman Death Investigator mystery, is an exploration of a fatal fire. To research this novel, Viets delved into the devastating consequences of junk science and arson investigations.

Fire and Ashes, my latest Angela Richman Death Investigator mystery, is an exploration of a fatal fire. To research this novel, I learned about the devastating consequences of junk science—that's untested science, and it's still used today in some arson investigations. By the way, deliberately set fires are officially "incendiary fires"—arson is the crime.

Like many mystery lovers, I thought I knew the signs of deadly arson fires.

If the investigator found alligator char—large, shiny char blisters on burned wood—the killer had used gasoline to start the fatal fire.

Pour patterns, irregularly shaped patterns on the burned floor, was another sign of spilled gasoline and the crime of arson. So was "crazing," or crazed glass, tiny cracks in glass.

Once the investigators found the signs, they photographed the evidence and arrested the killer.

Wrong. Those are examples of junk science, which has sent innocent people to death row. One was Todd Willingham, a Texas man who got the needle for burning his three children. Willingham was innocent, and his death compounded that family tragedy.

To research Fire and Ashes, I had multiple interviews with a fire investigator in Delray Beach, Florida. He recommended a long session with a textbook, Fire Investigator: Principles and Practice to NFPA 921 and 1033 Fourth Edition. This book is definitely not bedtime reading. NFPA 921's photos of burned bodies will keep you awake nights.

Florida arson expert John Lentini is one investigator who fights to discredit junk science and save the unjustly accused. Remember the Oakland Hills firestorm in October 1991? Reports say that wildfire killed some 25 people, injured 150, and destroyed almost 3,500 homes, condos and apartments. The losses were estimated at a billion and a half dollars.

But some good came out of that epic loss. Lentini was one of the investigators who studied the aftermath of the California wildfire. These experts found crazed glass, pour patterns, and other so-called signs of arson, when they knew the fires could not have been set deliberately. Crazed glass, for instance. Lentini told reporters crazing "used to be evidence of arson. You cannot make crazed glass by heating it rapidly, but you can by cooling it rapidly"—and firefighters' hoses can provide the rapid cooling.

As for alligator char, you've seen those large, shiny blisters on the logs in your fireplace—and you sure didn't start that fire with gasoline. And pour patterns? Lots of things can cause those, even improperly applied glue on wall-to-wall carpet.

Why does junk science persist? There aren't enough controlled scientific studies. And some investigators hang onto unproven fire folklore. When they were starting out, they heard the old-timers tell them about pour patterns, crazing and alligator char. Firefighters believed those old smoke eaters knew their craft—their conclusions didn't need to be tested.

Fire and Ashes tackles an incendiary mix: local prejudice and junk science. Death investigator Angela Richman, who works for the medical examiner in wealthy Chouteau County, Missouri, is in charge of the body at a fatal fire. She arrives at an exclusive, gated community as Luther Delor's body is carried out of his burning mansion. Luther is a scandalous 70. The old souse left his socialite wife for a 20-year-old Mexican-American manicurist, Kendra Salvato. Local gossip says the old man gave his pretty young mistress $2 million to wear his ring and she'll get another $2 million to marry him. The community that disapproved of Luther's bed hopping is united against Kendra. She's painted as a gold-digger killer, who set fire to her fiancé.

Angela has to gather the forensic facts during a firestorm of gossip, and hope cold, hard science can save Kendra.

Elaine Viets returns to her hardboiled roots with Brain Storm, the first Angela Richman Death Investigator mystery, which debuted in 2017. Elaine passed the Medicolegal Death Investigators Training Course for forensic professionals. She's written 29 mysteries in three bestselling series. The Art of Murder is her 15th Dead-End Job mystery.