[Yohuru Williams] Downtown Minneapolis bustling North Loop neighborhood has a trendy sheen that belies a violent history.

In 1934, these streets were stained with blood during the infamous 1934 truckers strike.

[Reporter] In Minneapolis, a truck driver strike was climaxed by severe riots and fights between the strikers and the police.

That witnessed one of the most alarming instances of deadly force used by the government or police in the state's history.

It's a moment that underscores the paradox of a police union, an entity that will become a bruising political force in the city in the early 21st century.

But that began as a real attempt to give police workers rights and protections in the early 20th century.

(pensive music) Minneapolis Mayor Thomas Van Leer is one of a small number of socialists to become mayor of a large American city, when he was elected in 1916.

As he took the reins in City Hall, like the mayors before and since, he quickly set to reforming the Minneapolis Police Department, including upping pay to lessen the temptation for graft.

He also appointed a fellow labor organizer and union member as chief.

[Michael Lansing] What you see is police officers themselves starting to think about like, maybe we should have a union, too.

They emerge in the early 1920s is a pretty important force.

They're not engaged in collective bargaining, but they do represent the needs of police officers as city employees.

And they are actually even starting to participate in the local labor movement at the head of Labor Day parades here in the city of Minneapolis in the mid 1920s.

[Yohuru] But Minneapolis was not a union town, and a circle of local business leaders, The Citizens Alliance, initially tolerated but eventually went after the Federation just like it did any other union in the city.

The Citizens Alliance actually forced the police officers in 1927 to renounce their notions of a union.

The Police Officers Federation remains, but it's essentially an association rather than a labor organization.

[Yohuru] This led to the pivotal moment in 1934.

[Michael] It's a moment of ntense public disorder in what is already a really unsettling time.

So hundreds and hundreds of people are in the streets in the North Loop.

Strikers, protesters, as well as police officers.

But those police officers are joined by these special deputies.

These are recently deputized citizens, mostly representing business interests.

Some of them are even small business owners, and they are there alongside the cops to have a show of force, a law and order show of force in the streets to ensure that this strike gets taken care of.

(gunshot) [Reporter] In Minneapolis, a truck driver strike was climaxed by severe riots and fights between the strikers and the police, with many casualties.

[Yohuru] Strikers arriving in trucks were drawn into what some researchers have described as an ambush.

Minneapolis police opened fire.

Several strikers were killed by police gunfire and dozens were injured.

It's often said wounds produce narratives.

What is the narrative for the police coming out of 1934?

What are the lessons learned?

They have to line up.

They have to make sure that they are doing the work that the mayor and anyone who's bringing pressure on the mayor wants them to do.