Here are five key takeaways from the Clarion Ledger's investigation into Mississippi's prison crisis.

Four factors contributed to the crisis, experts say

After an eruption of violence at Mississippi prisons, many were left wondering: How did we get here? Who is at fault?

According to inmates and experts interviewed by the Clarion Ledger, including a former corrections commissioner, a longtime prison monitor and advocates for reform, factors include:

Sentencing policies leading to high rates of incarceration Political appointments of corrections commissioners who had no experience running prisons Funding cuts to the Mississippi Department of Corrections by Mississippi lawmakers MDOC's lack of transparency

Read the story here:Mississippi prisons 'a ticking time bomb' How did we get here? Who's at fault?

More people were killed in prison in January than any other year in recent memory

In January alone, there were more prison homicides than the total for any other year since at least 2014. One longtime prison watchdog said the level of violence was unprecedented in recent memory.

Since Dec. 29, 22 people have died while in custody of MDOC.

Analysis: For inmates, Mississippi is a deadlier state than most. This year could be a record

The founding of Mississippi's oldest and most infamous prison was rooted in brutality and racism

Historically known as Parchman Farm, the Mississippi State Penitentiary was established in 1901 and now occupies a sprawling 18,000 acres in the heart of the fertile Delta. It was, as Historian David Oshinsky said, "the closest thing to slavery that survived the Civil War.”

Now some activists — including celebrities Jay-Z and Yo Gotti — are calling on the state to shut down Parchman and end its "legacy of despair" forever.

Learn more:Hard time, brutal conditions: A history of Parchman prison

Mississippi has one of the highest prison mortality rates in the country

A new report from the U.S. Department of Justice's Bureau of Justice Statistics shows Mississippi's inmate mortality rate was tied with Tennessee for fourth in the nation in 2016, the most recent available data.

Nationwide the rate of deaths in state prisons increased from 296 to 303 per 100,000 state prisoners between 2015 and 2016. Mississippi's prisoner mortality rate in 2016 was 474 per 100,000 inmates.

Analysis: For inmates, Mississippi is a deadlier state than most. This year could be a record

Mississippi now incarcerates people at a higher rate than all but one other state

Harsh sentencing laws and lack of early release programs swell the prison population, now putting Mississippi second in the nation for incarceration rates.

The proof of "over-incarceration" is in the numbers, Mississippi State Public Defender Andre de Gruy said. While Mississippi ranks near the middle when comparing crime rates across states, the Magnolia state now has one of the highest incarceration rates in the nation.

Timeline: 180 years of Mississippi prison history

Contact Alissa Zhu at azhu@gannett.com. Follow @AlissaZhu on Twitter.