- [Geoffrey] One smoky night in June of 1924, a crime right out of the Wild West began in downtown Chicago.

Two bandits snuck aboard a mail train leaving Union Station.

In those days, mail trains carried valuable merchandise, like bonds, jewels, and even sacks of cash.

Heading north, this particular train reached a rural junction, known as Rondout, near Libertyville, and those bandits were about to pull off the largest train robbery in American history.

How much money do you think is still out there?

- There's estimates that maybe just a little over a million.

Could still be out there somewhere, though- - Nicole Stocker from the Lake County Forest Preserve district took me to the scene of the crime.

She told me that when the train reached Rondout the two robbers climbed over the tender and into the cab of the engine with their guns drawn.

- And surprised the engineer and firemen who did not expect two men to come aboard.

So they told them they had to stop the train and they had guns in different things.

- [Geoffrey] The robbers were part of the notorious Newton Gang, four brothers from Texas, plus a number of accomplices, including an explosives expert named Brent Glasscock.

- The rest of the group was waiting in stolen Cadillacs.

- Stolen Cadillacs.

- Stolen Cadillacs.

- [Geoffrey] Not just like a stolen Ford or something?

- [Nicole] No.

And as soon as the train stopped, the rest of the group came out.

They knew exactly which car they wanted to target.

- [Geoffrey] The Newton boys clearly had inside information.

In less than 30 minutes, the gang had gathered a take worth an estimated $2 million.

That would be worth more than $37 million today.

And it all would've gone great, except for what?

- Well, during the course of this, one of the members of the group, Brent Glasscock, mistook another of their group as a train worker, and he shot him five different times.

He didn't realize who he was hitting.

- [Geoffrey] It was Doc Newton.

The gang piled the badly wounded Newton brother on top of some of the mail sacks in one of the Cadillacs, and made their getaway.

- And at least part of the group went back into Chicago to try to treat the injured brother.

- [Geoffrey] While a large portion of the money was never found, police soon found the robbers, - [Nicole] And it's still debated exactly who tipped them off, but somehow they were given an address to an apartment in Chicago, and when they got there, they found the injured brother with others in the group.

- Who's the insider in all of this.

- So the person who they eventually discovered was involved was William Fahy.

- [Geoffrey] As in Chicago postal inspector William Fahy.

He'd been a rising star in his field and gained notoriety for solving train robberies.

- He maintains his innocence until his death though, and says that he was framed for this crime by others who were jealous of his skill at solving train robberies.

- [Geoffrey] Doc survived and he and the rest of the Newtons received sentences from a year and a day to 12 years.

After being released, the Newtons returned to their lives of crime into their old age, and Joe Newton was interviewed on late night television.

- Now when's the first time you went to jail?

That Rondout train robbery.

- Yeah?

- Yes.

- I thought you were gonna put that on to stick me out.

(audience laughing) - You thought I was going to?

- Yeah, old habits die hard.

Don't they know?

(tense music) (inquisitive music)