A cold case and a blood test

Spring should have been a busy time at the greenhouse on Indian Trail. But the owner, Warren Lincoln, had vanished.

In late April 1923, someone ransacked his house. Police found blood at the scene, and Lincoln was gone. Lincoln's brother-in-law and wife -- who reportedly left Lincoln in January -- and a mysterious stranger were the prime suspects.

Aurora Police Chief Frank Michels, a stern man with a baby face, quietly combed through the evidence he had collected from Lincoln's house, including a book he found next to Lincoln's bed -- Silent, White and Beautiful by Tod Robbins. The story was about a French man who murdered his nagging wife, then hid her body inside a plaster statue he kept in his house. Considering that it was found at a crime scene, the story had an extra chill.

Privately, Michels didn't believe the story the press had latched on to -- that Lincoln had been murdered.

The chief's theory gained traction when he received an odd letter, typed in green ink, from someone who claimed to have seen Lincoln commit suicide in Baltimore. Michels' gut said this letter was a lie, but he had little proof either way. He needed evidence.

He ordered the latest in blood analysis, an "Abrams Test," based on the theory that everyone's blood has a unique vibration.

First, lab technicians poured some blood into a bowl that had wires attached to it.

Next, a person -- the "controller" -- held both ends of the wire as the blood was vibrated.

The number of vibrations showed whether the blood was human, and if it was a man's or woman's. The test ended when a second person tapped the controller's abdomen and heard a wooden, rather than clear sound.

The test showed the blood on Lincoln's window belonged to a man who was eccentric and suffering from a disease. The test later turned out to be dead wrong.

The test didn't matter to Michels. He was already on his way to Chicago. Michels had figured out what happened to Lincoln.

The murder victim was alive.