According to author Bryan Burrough in "Public Enemies," the criminal credited with introducing a new level of professionalism to bank robbery was Herman K. Lamm, a German émigré known as “The Baron.” Born in 1880, Lamm is a quasimythic figure; some claim he began his career with the Hole-in-the-Wall Gang. What is known is that around 1917, while in a Utah prison, he developed a rigorous system for robbing banks. Lamm pioneered the “casing” of banks, the observation of bank guards, alarms, and tellers; a bank was known as a “jug,” and an expert caser of banks was known as a “jug marker.” Each member of Lamm’s gang was assigned a role in the robbery: the lookout, the getaway driver, the lobby man, the vault man. Most important, Lamm is credited with devising the first detailed getaway maps, or “gits.” Once he targeted a bank, Lamm mapped the nearby back roads, known as “cat roads,” to a tenth of a mile, listing each landmark and using a stopwatch to time distances. Any teenager with a birdgun could rob a bank; it was getting away that posed a challenge. 

Lamm’s detailed gits, clipped to the dashboard of a car, took the guesswork out of the getaway. His gang was credited with dozens of robberies during the 1920s, until Lamm was shot and killed near Clinton, Indiana, in 1930. By then his system had been widely imitated.