Dr. Calvin Goddard, a pioneer of forensic ballistics set in motion one of the most widely used techniques of analysing bullets. He developed the original strategies for matching bullets to guns in the early 1900's.
While investigating the St.valentine's day massacre which occured 14th February 1929 in Chicago. Goddard came up with a way to match the bullets to the gun they were fired from.
He arrived at a crime scene where 7 mob associted men had been gunned down excecution style. A bombardment of bullets had reigned down on the victims. It was Goddards job to identify the types of gun used.
Over 70 rounds of ammunition were recovered from the scene, Goddard identified they were looking for Tommy Guns. After the investigation progressed officers recovered two Thompson submachine guns from a bungalow in Michigan during a search of a property suspected to be linked to the shooting.
Goddard then began to match the marks left on the casings recovered from the crime scene, with the marks left on the casings he shot from the two recovered Tommy Guns. They were a match.
When a bullet is fired from a gun marks are left on the bullet or cartridge case. These marks are like a fingerprint they are unique to the gun they are fired from. This type of forensic science is known as pattern recognition and is now used all over the world in crime scene analysis.
This was one of the earliest uses of ballistics evidence in US history.