The bullet from Berardelli's body that prosecutors said matched Sacco's Colt — but defense experts disputed

April 15, 1920, in South Braintree, Massachusetts.

A paymaster and a guard were walking along Pearl Street, carrying two boxes of payroll cash.

About $15,776.

Two men approached them and opened fire.

Both men were killed on the street.

The gunmen grabbed the boxes, jumped into a waiting Buick, and fled with several accomplices.

Witnesses described the shooters as Italian-looking men.

That is what the record shows.

Who those two shooters were is not established at this point.

The identities would become the whole case.

An ordinary errand — carrying a factory payroll — turned into a double murder.

The money was the point.

The men who took it were gone before the bodies settled.

The robbery itself was over in minutes.

But the case was just beginning.

It became one of the most famous criminal cases of the 1920s.

Not because of the violence alone, though the violence was sudden and complete.

Because of the political climate.

The two men eventually charged were Italian-born anarchists.

Their trial became a global cause célèbre.

But on that April morning, there was only the street, the boxes, and the gunfire.

Two dead men.

A Buick disappearing.

And a question that would take seven years to answer, and never fully settle.

Who were the shooters?

The record does not say.

Not yet.

THE ARREST ON THE STREETCAR

The police were looking for Italian anarchists.

The 1919 bombing campaign had left the country on edge, and the South Braintree murders fit a pattern they believed they understood.

On May 5, 1920, they stopped a streetcar in Brockton, Massachusetts.

Inside were Nicola Sacco and Bartolomeo Vanzetti.

Both men were armed.

Sacco carried a .32-caliber Colt automatic pistol; Vanzetti had a .38-caliber revolver.

The police said the two men lied about where they had been and what they had done.

They said the men lied about their anarchist activities.

That is a police claim.

The record does not establish that they lied.

Two armed anarchists, arrested weeks after the robbery.

The prosecution would build its case on that weight of circumstance.

They would also build it on eyewitnesses.

One witness claimed she saw Sacco in the fleeing car.

She said she saw him at a distance, in motion, for a matter of seconds.

Her testimony became a pillar of the prosecution's case.

The defense would later call a witness who placed Sacco in Boston at the time of the murders.