The St Valentine's Day Massacre on 14 February 1929 led to the establishment of the first crime detection laboratory in the United States of America.

When one thinks of the St Valentine’s Day Massacre, one thinks of Al Capone and Bugs Moran shooting it out with machine guns in a red-brick warehouse in Chicago in 1929.

Well, that is only part of the story – the St Valentine’s Day Massacre is really a story about ballistics and a man named Calvin Goddard from the Bureau of Forensic Ballistics in New York City — the same Calvin Goddard who had confirmed the ballistics evidence in the Sacco and Vanzetti case two years earlier. And Capone and Moran - well, they weren't even actually there!

So, What Really Happened St Valentine’s Day 1929?

According to Crimelibrary, seven men were waiting that morning around 10:30 a.m. in a red brick warehouse for the S-M-C Cartage Company on Chicago's North Side, at 2122 North Clark Street. Three men wearing police uniforms and two dressed as civilians arrived in a police car and went inside. Witnesses in the neighborhood heard multiple gunshots made by machine guns.

Then the police left, and a dog inside left alive the building began to bark and howl. Neighbors checked and found a bloody scene: the seven unarmed men lay on the floor, all shot in the back multiple times. The wall against which they had been lined up for the assassination was a gory mess.

The victims, according to the History Channels' Forensic Firsts, were known associates of mobster George "Bugs" Moran of the North Side Irish Gang. He pointed the finger at Al Capone of the South Side Italian Gang. Capone, who was down in Florida at the time of the St Valentine’s Day Massacre, pointed it back at him.

Evidence Processing in the St Valentine’s Day Massacre in Chicago

The shooters had left behind 70 empty 45 caliber cartridge casings and the weapons that fired them were identified by Calvin Goddard as .45-caliber Thomson submachine guns.

By differentiating two distinct sets of ejector marks on the cartridge case, Goddard determined that two weapons had fired the seventy shells. Fifty cartridges had been fired from one Thompson and twenty from the other.

The bullets all contained two manufacturer's marks made by the U.S. Cartridge Company. Goddard learned that ammunition marks like this had only been produced during the period July, 1927 to July, 1928.

Police are Under Suspicion– Goddard Clears them

Police had a big problem at the time; many people thought they had killed a gang in cold blood, so it was left to ballistics and firearms comparisons to unearth the true story.

Goddard was brought down from New York as an independent investigator. After he established the make of the weapon, he fired each of the eight Thompson machine guns owned by the Chicago police. He then compared the results to evidence collected at the scene. No casings matched, which cleared the police.

Comparison Microscope used to prove Guilt or Innocence

With the recent invention of the comparison microscope by Goddard's partner, two objects could be laid side-by-side for high-powered comparative examination using a series of reflective mirrors and lenses.

Because the police were cleared, Calvin Goddard concluded that someone had impersonated police officers to commit the murders.

Ten months after the St Valentine’s Day Massacre, the police raided the home of a hit man for Al Capone. They found two machine guns, which they gave to Goddard to take to his ballistics lab. He test-fired them and proved they were the weapons used in the massacre. That sent at least one of the killers to prison.

First Independent Crime Laboratory in America is Established

Goddard's work with ballistics inspired two businessmen who had been on the coroner's jury to set him up at Northwestern University in Chicago in the first independent crime laboratory in the country. Ballistics, fingerprinting, blood analysis and trace evidence were brought under one roof and the lab became a prototype.

Other Sources:

St Valentine's Day Massacre - with newspapers and pictures of this landmark event